diff --git a/.gitignore b/.gitignore
index f5d6fe310..ad5377f1a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,3 +28,6 @@ compile_commands.json
 data/tpch/**/*.parquet
 .idea
 lib/.idea
+
+check_duckdb
+wasm_setup
diff --git a/Makefile b/Makefile
index a00b6f5d3..132753ad2 100644
--- a/Makefile
+++ b/Makefile
@@ -28,6 +28,7 @@ JS_FILTER=
 EXTENSION_CACHE_DIR="${ROOT_DIR}/.ccache/extension"
 EXCEL_EXTENSION_CACHE_FILE="${EXTENSION_CACHE_DIR}/excel"
 JSON_EXTENSION_CACHE_FILE="${EXTENSION_CACHE_DIR}/json"
+CUSTOM_EXTENSION_ENVIRONMENT=DUCKDB_WEB_CUSTOM_EXTENSION_DIRS="${CUSTOM_EXTENSION_DIRS}"
 
 cpp_lib: lib_tests
 
@@ -256,27 +257,43 @@ wasm_setup: set_environment check_duckdb wrapped_wasm_caches
 
 .PHONY: wasm_dev
 wasm_dev: wasm_setup
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh dev mvp
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh dev eh
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh dev coi
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh dev mvp
+ifneq (${DUCKDB_SKIP_BUILD_EH}, 1)
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh dev eh
+endif
+ifneq (${DUCKDB_SKIP_BUILD_COI}, 1)
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh dev coi
+endif
 
 .PHONY: wasm_relperf
 wasm_relperf: wasm_setup
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relperf mvp
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relperf eh
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relperf coi
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relperf mvp
+ifneq (${DUCKDB_SKIP_BUILD_EH}, 1)
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relperf eh
+endif
+ifneq (${DUCKDB_SKIP_BUILD_COI}, 1)
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relperf coi
+endif
 
 .PHONY: wasm_relsize
 wasm_relsize: wasm_setup
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relsize mvp
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relsize eh
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relsize coi
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relsize mvp
+ifneq (${DUCKDB_SKIP_BUILD_EH}, 1)
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relsize eh
+endif
+ifneq (${DUCKDB_SKIP_BUILD_COI}, 1)
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh relsize coi
+endif
 
 .PHONY: wasm_debug
 wasm_debug: wasm_setup
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh debug mvp
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh debug eh
-	${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh debug coi
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh debug mvp
+ifneq (${DUCKDB_SKIP_BUILD_EH}, 1)
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh debug eh
+endif
+ifneq (${DUCKDB_SKIP_BUILD_COI}, 1)
+	${CUSTOM_EXTENSION_ENVIRONMENT} ${EXEC_ENVIRONMENT} ${ROOT_DIR}/scripts/wasm_build_lib.sh debug coi
+endif
 
 wasm: wasm_relperf
 
@@ -397,7 +414,6 @@ eslint:
 # Install all yarn packages
 .PHONY: yarn_install
 yarn_install:
-	yarn
 	yarn install
 
 .PHONY: examples
diff --git a/examples/bare-browser/package.json b/examples/bare-browser/package.json
index 7c6322a3c..38cc9deb3 100644
--- a/examples/bare-browser/package.json
+++ b/examples/bare-browser/package.json
@@ -5,7 +5,7 @@
     "main": "index.js",
     "license": "MIT",
     "dependencies": {
-        "@duckdb/duckdb-wasm": "file:../../packages/duckdb-wasm"
+        "@duckdb/duckdb-wasm": "1.11.0"
     },
     "devDependencies": {
         "http-server": "^14.1.1"
diff --git a/examples/bare-node/package.json b/examples/bare-node/package.json
index 8800d9a0f..c68dfca4f 100644
--- a/examples/bare-node/package.json
+++ b/examples/bare-node/package.json
@@ -5,7 +5,7 @@
     "main": "index.js",
     "license": "MIT",
     "dependencies": {
-        "@duckdb/duckdb-wasm": "file:../../packages/duckdb-wasm"
+        "@duckdb/duckdb-wasm": "1.11.0"
     },
     "scripts": {
         "test": "node ./index.cjs"
diff --git a/examples/esbuild-browser/package.json b/examples/esbuild-browser/package.json
index 531c91589..8dd417922 100644
--- a/examples/esbuild-browser/package.json
+++ b/examples/esbuild-browser/package.json
@@ -5,7 +5,7 @@
     "main": "index.js",
     "license": "MIT",
     "dependencies": {
-        "@duckdb/duckdb-wasm": "file:../../packages/duckdb-wasm"
+        "@duckdb/duckdb-wasm": "1.11.0"
     },
     "devDependencies": {
         "esbuild": "^0.19.5",
diff --git a/examples/esbuild-node/package.json b/examples/esbuild-node/package.json
index 876fa735b..ea480b1e0 100644
--- a/examples/esbuild-node/package.json
+++ b/examples/esbuild-node/package.json
@@ -5,7 +5,7 @@
     "main": "index.js",
     "license": "MIT",
     "dependencies": {
-        "@duckdb/duckdb-wasm": "file:../../packages/duckdb-wasm"
+        "@duckdb/duckdb-wasm": "1.11.0"
     },
     "devDependencies": {
         "esbuild": "^0.19.5",
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 60a692282..a183e14be 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -10,6 +10,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(ignoreMe "${DUCKDB_WASM_VERSION}")
+set(DUCKDB_WEB_CUSTOM_EXTENSION_DIRS $ENV{DUCKDB_WEB_CUSTOM_EXTENSION_DIRS})
 
 option(DUCKDB_WASM_LOADABLE_EXTENSIONS "Build with loadable extensions" OFF)
 option(DUCKDB_WASM_LOADABLE_EXTENSIONS_UNSIGNED "Build with loadable extensions" OFF)
@@ -287,6 +288,40 @@ target_link_libraries(duckdb_web_parquet duckdb duckdb_parquet)
 target_link_libraries(duckdb_web_excel duckdb duckdb_excel)
 target_link_libraries(duckdb_web_json duckdb duckdb_json)
 
+# ---------------------------------------------------------------------------
+# Custom extensions
+
+macro(register_custom_extension name lib)
+  set(DUCKDB_WEB_CUSTOM_EXTENSION_NAMES "${DUCKDB_WEB_CUSTOM_EXTENSION_NAMES};${name}" PARENT_SCOPE)
+  set(DUCKDB_WEB_CUSTOM_EXTENSION_LIBS "${DUCKDB_WEB_CUSTOM_EXTENSION_LIBS};${lib}" PARENT_SCOPE)
+endmacro()
+
+set(DUCKDB_WEB_CUSTOM_EXTENSION_NAMES "")
+set(DUCKDB_WEB_CUSTOM_EXTENSION_LIBS "")
+
+if(DUCKDB_WEB_CUSTOM_EXTENSION_DIRS)
+  foreach(dir ${DUCKDB_WEB_CUSTOM_EXTENSION_DIRS})
+    message(STATUS "Adding custom extension dir ${dir}")
+    add_subdirectory(${dir} ${CMAKE_BINARY_DIR}/${dir})
+  endforeach()
+endif()
+
+foreach(lib ${DUCKDB_WEB_CUSTOM_EXTENSION_LIBS})
+  target_link_libraries(duckdb_web ${lib})
+endforeach()
+
+set(GENERATED_HEADER_FILE ${PROJECT_BINARY_DIR}/codegen/include/duckdb/generated_extensions_header.hpp)
+set(DUCKDB_WEB_CUSTOM_EXTENSION_INIT_FUNCTIONS "")
+set(DUCKDB_WEB_CUSTOM_EXTENSION_INIT_CALLS "")
+
+foreach(name ${DUCKDB_WEB_CUSTOM_EXTENSION_NAMES})
+  set(DUCKDB_WEB_CUSTOM_EXTENSION_INIT_FUNCTIONS "${DUCKDB_WEB_CUSTOM_EXTENSION_INIT_FUNCTIONS}extern void ${name}_init(duckdb::DuckDB *db);")
+  set(DUCKDB_WEB_CUSTOM_EXTENSION_INIT_CALLS "${DUCKDB_WEB_CUSTOM_EXTENSION_INIT_CALLS}${name}_init(db);")
+endforeach()
+
+configure_file(${CMAKE_SOURCE_DIR}/extension/generated_custom_extensions_header.hpp.in ${GENERATED_HEADER_FILE})
+include_directories(${PROJECT_BINARY_DIR}/codegen/include)
+
 # ---------------------------------------------------------------------------
 # Emscripten
 
@@ -305,6 +340,8 @@ if(EMSCRIPTEN)
       -s WARN_ON_UNDEFINED_SYMBOLS=0 \
       -s ALLOW_MEMORY_GROWTH=1 \
       -s MAXIMUM_MEMORY=4GB \
+      -s INITIAL_MEMORY=32MB \
+      -s STACK_SIZE=16MB \
       -s MODULARIZE=1 \
       -s EXPORT_NAME='DuckDB' \
       -s EXPORTED_FUNCTIONS='[ \
diff --git a/lib/extension/CMakeLists.template.txt b/lib/extension/CMakeLists.template.txt
new file mode 100644
index 000000000..9b4ed0c05
--- /dev/null
+++ b/lib/extension/CMakeLists.template.txt
@@ -0,0 +1,9 @@
+# This is a CMake file template for a custom extension.
+# This file is expected to be copied to the extension directory, and specified via
+# `CUSTOM_EXTENSION_DIRS` variable for duckdb-wasm Makefile.
+
+cmake_minimum_required(VERSION 3.10)
+
+# This CMake file is expected to call `register_custom_extension` to tell
+# duckdb-wasm CMake file to link the custom extension library and call the init-function at the startup.
+register_custom_extension("libhello_ext" "/path/to/libhello_ext.a")
diff --git a/lib/extension/generated_custom_extensions_header.hpp.in b/lib/extension/generated_custom_extensions_header.hpp.in
new file mode 100644
index 000000000..24266073d
--- /dev/null
+++ b/lib/extension/generated_custom_extensions_header.hpp.in
@@ -0,0 +1,14 @@
+#ifndef DUCKDB_WASM_GENERATED_CUSTOM_EXTENSIONS_HEADER_HPP
+#define DUCKDB_WASM_GENERATED_CUSTOM_EXTENSIONS_HEADER_HPP
+
+#include "duckdb/main/database.hpp"
+
+extern "C" {
+${DUCKDB_WEB_CUSTOM_EXTENSION_INIT_FUNCTIONS}
+}
+
+void LoadCustomExtensions(duckdb::DuckDB *db) {
+    ${DUCKDB_WEB_CUSTOM_EXTENSION_INIT_CALLS}
+}
+
+#endif  // DUCKDB_WASM_GENERATED_CUSTOM_EXTENSIONS_HEADER_HPP
diff --git a/lib/src/webdb.cc b/lib/src/webdb.cc
index 096db4bc3..430ebe002 100644
--- a/lib/src/webdb.cc
+++ b/lib/src/webdb.cc
@@ -62,6 +62,7 @@
 #include "duckdb/web/udf.h"
 #include "duckdb/web/utils/debug.h"
 #include "duckdb/web/utils/wasm_response.h"
+#include "duckdb/generated_extensions_header.hpp"
 #include "rapidjson/document.h"
 #include "rapidjson/error/en.h"
 #include "rapidjson/rapidjson.h"
@@ -829,6 +830,7 @@ arrow::Status WebDB::Open(std::string_view args_json) {
         duckdb_web_json_init(db.get());
 #endif
 #endif  // WASM_LOADABLE_EXTENSIONS
+        LoadCustomExtensions(db.get());
         RegisterCustomExtensionOptions(db);
 
         // Reset state that is specific to the old database
diff --git a/packages/benchmarks/package.json b/packages/benchmarks/package.json
index c95d7c455..a3d0bc2cc 100644
--- a/packages/benchmarks/package.json
+++ b/packages/benchmarks/package.json
@@ -4,7 +4,7 @@
     "license": "MIT",
     "private": true,
     "dependencies": {
-        "@duckdb/duckdb-wasm": "file:../duckdb-wasm",
+        "@duckdb/duckdb-wasm": "1.11.0",
         "apache-arrow": "^13.0.0",
         "apache-arrow-3": "npm:apache-arrow@^3.0.0",
         "arquero": "^5.2.0",
diff --git a/packages/duckdb-wasm-app/package.json b/packages/duckdb-wasm-app/package.json
index b44e1a07b..f1a80a73f 100644
--- a/packages/duckdb-wasm-app/package.json
+++ b/packages/duckdb-wasm-app/package.json
@@ -18,8 +18,8 @@
         "node": ">=14.13"
     },
     "dependencies": {
-        "@duckdb/duckdb-wasm": "file:../duckdb-wasm",
-        "@duckdb/duckdb-wasm-shell": "file:../duckdb-wasm-shell",
+        "@duckdb/duckdb-wasm": "1.11.0",
+        "@duckdb/duckdb-wasm-shell": "1.11.0",
         "apache-arrow": "^13.0.0",
         "bootstrap": "^5.3.2",
         "classnames": "^2.3.2",
@@ -54,6 +54,7 @@
         "file-loader": "^6.2.0",
         "html-webpack-plugin": "^5.5.3",
         "jasmine-core": "^5.1.1",
+        "ifdef-loader": "^2.3.2",
         "jasmine-spec-reporter": "^7.0.0",
         "karma": "^6.4.2",
         "karma-chrome-launcher": "^3.2.0",
diff --git a/packages/duckdb-wasm-app/src/app.tsx b/packages/duckdb-wasm-app/src/app.tsx
index 38d4c245e..904ba4f47 100644
--- a/packages/duckdb-wasm-app/src/app.tsx
+++ b/packages/duckdb-wasm-app/src/app.tsx
@@ -14,18 +14,27 @@ import 'react-popper-tooltip/dist/styles.css';
 
 import * as duckdb from '@duckdb/duckdb-wasm';
 import duckdb_wasm from '@duckdb/duckdb-wasm/dist/duckdb-mvp.wasm';
+/// #if EH_BUILD_ENABLED
 import duckdb_wasm_eh from '@duckdb/duckdb-wasm/dist/duckdb-eh.wasm';
+/// #endif
+/// #if COI_BUILD_ENABLED
 import duckdb_wasm_coi from '@duckdb/duckdb-wasm/dist/duckdb-coi.wasm';
+/// #endif
 
 const DUCKDB_BUNDLES: duckdb.DuckDBBundles = {
     mvp: {
         mainModule: duckdb_wasm,
         mainWorker: new URL('@duckdb/duckdb-wasm/dist/duckdb-browser-mvp.worker.js', import.meta.url).toString(),
     },
+    /// #if EH_BUILD_ENABLED
     eh: {
         mainModule: duckdb_wasm_eh,
         mainWorker: new URL('@duckdb/duckdb-wasm/dist/duckdb-browser-eh.worker.js', import.meta.url).toString(),
     },
+    /// #else
+    eh: undefined,
+    /// #endif
+    /// #if COI_BUILD_ENABLED
     coi: {
         mainModule: duckdb_wasm_coi,
         mainWorker: new URL('@duckdb/duckdb-wasm/dist/duckdb-browser-coi.worker.js', import.meta.url).toString(),
@@ -34,6 +43,9 @@ const DUCKDB_BUNDLES: duckdb.DuckDBBundles = {
             import.meta.url,
         ).toString(),
     },
+    /// #else
+    coi: undefined,
+    /// #endif
 };
 const logger = new duckdb.ConsoleLogger(duckdb.LogLevel.WARNING);
 
diff --git a/packages/duckdb-wasm-app/webpack.common.js b/packages/duckdb-wasm-app/webpack.common.js
index 99fe6f52e..e6bf708ac 100644
--- a/packages/duckdb-wasm-app/webpack.common.js
+++ b/packages/duckdb-wasm-app/webpack.common.js
@@ -33,9 +33,20 @@ export function configure(params) {
                 },
                 {
                     test: /\.tsx?$/,
-                    loader: 'ts-loader',
                     exclude: /node_modules/,
-                    options: params.tsLoaderOptions,
+                    use: [
+                        {
+                            loader: 'ts-loader',
+                            options: params.tsLoaderOptions,
+                        },
+                        {
+                            loader: 'ifdef-loader',
+                            options: {
+                                EH_BUILD_ENABLED: process.env['DUCKDB_SKIP_BUILD_EH'] !== '1',
+                                COI_BUILD_ENABLED: process.env['DUCKDB_SKIP_BUILD_COI'] !== '1',
+                            },
+                        },
+                    ],
                 },
                 {
                     test: /\.css$/,
diff --git a/packages/duckdb-wasm-shell/package.json b/packages/duckdb-wasm-shell/package.json
index 8ca0cbdde..c586bab7c 100644
--- a/packages/duckdb-wasm-shell/package.json
+++ b/packages/duckdb-wasm-shell/package.json
@@ -24,7 +24,7 @@
         "csv"
     ],
     "dependencies": {
-        "@duckdb/duckdb-wasm": "file:../duckdb-wasm",
+        "@duckdb/duckdb-wasm": "1.11.0",
         "xterm": "^5.1.0",
         "xterm-addon-fit": "^0.7.0",
         "xterm-addon-web-links": "^0.9.0",
diff --git a/packages/duckdb-wasm/bundle.mjs b/packages/duckdb-wasm/bundle.mjs
index 005371cb5..428c1ee26 100644
--- a/packages/duckdb-wasm/bundle.mjs
+++ b/packages/duckdb-wasm/bundle.mjs
@@ -4,6 +4,7 @@ import path from 'path';
 import { rimrafSync } from 'rimraf';
 import mkdir from 'make-dir';
 import { fileURLToPath } from 'url';
+import ifdef from 'esbuild-plugin-ifdef'
 
 // -------------------------------
 // Current bundling strategy
@@ -56,6 +57,14 @@ function printErr(err) {
     if (err) return console.log(err);
 }
 
+function ehBuildEnabled() {
+    return process.env['DUCKDB_SKIP_BUILD_EH'] !== '1';
+}
+
+function coiBuildEnabled() {
+    return process.env['DUCKDB_SKIP_BUILD_COI'] !== '1';
+}
+
 // Patch broken arrow package.json
 // XXX Remove this hack as soon as arrow fixes the exports
 function patch_arrow() {
@@ -101,6 +110,10 @@ fs.copyFile(path.resolve(src, 'bindings', 'duckdb-coi.wasm'), path.resolve(dist,
     // -------------------------------
     // Browser bundles
 
+    const pluginConfig = [
+        ifdef(ehBuildEnabled() ? { EH_BUILD_ENABLED: true } : {}),
+    ];
+
     console.log('[ ESBUILD ] duckdb-browser.cjs');
     await esbuild.build({
         entryPoints: ['./src/targets/duckdb.ts'],
@@ -145,6 +158,7 @@ fs.copyFile(path.resolve(src, 'bindings', 'duckdb-coi.wasm'), path.resolve(dist,
             'process.release.name': '"browser"',
             'process.env.NODE_ENV': '"production"',
         },
+        plugins: pluginConfig,
     });
 
     console.log('[ ESBUILD ] duckdb-browser-blocking.mjs');
@@ -162,6 +176,7 @@ fs.copyFile(path.resolve(src, 'bindings', 'duckdb-coi.wasm'), path.resolve(dist,
             'process.release.name': '"browser"',
             'process.env.NODE_ENV': '"production"',
         },
+        plugins: pluginConfig,
     });
 
     console.log('[ ESBUILD ] duckdb-browser-mvp.worker.js');
@@ -179,49 +194,53 @@ fs.copyFile(path.resolve(src, 'bindings', 'duckdb-coi.wasm'), path.resolve(dist,
         define: { 'process.release.name': '"browser"' },
     });
 
-    console.log('[ ESBUILD ] duckdb-browser-eh.worker.js');
-    await esbuild.build({
-        entryPoints: ['./src/targets/duckdb-browser-eh.worker.ts'],
-        outfile: 'dist/duckdb-browser-eh.worker.js',
-        platform: 'browser',
-        format: 'iife',
-        globalName: 'duckdb',
-        target: TARGET_BROWSER,
-        bundle: true,
-        minify: true,
-        sourcemap: is_debug ? 'inline' : true,
-        external: EXTERNALS_WEBWORKER,
-        define: { 'process.release.name': '"browser"' },
-    });
+    if (ehBuildEnabled()) {
+        console.log('[ ESBUILD ] duckdb-browser-eh.worker.js');
+        await esbuild.build({
+            entryPoints: ['./src/targets/duckdb-browser-eh.worker.ts'],
+            outfile: 'dist/duckdb-browser-eh.worker.js',
+            platform: 'browser',
+            format: 'iife',
+            globalName: 'duckdb',
+            target: TARGET_BROWSER,
+            bundle: true,
+            minify: true,
+            sourcemap: is_debug ? 'inline' : true,
+            external: EXTERNALS_WEBWORKER,
+            define: { 'process.release.name': '"browser"' },
+        });
+    }
 
-    console.log('[ ESBUILD ] duckdb-browser-coi.worker.js');
-    await esbuild.build({
-        entryPoints: ['./src/targets/duckdb-browser-coi.worker.ts'],
-        outfile: 'dist/duckdb-browser-coi.worker.js',
-        platform: 'browser',
-        format: 'iife',
-        globalName: 'duckdb',
-        target: TARGET_BROWSER,
-        bundle: true,
-        minify: true,
-        sourcemap: is_debug ? 'inline' : true,
-        external: EXTERNALS_WEBWORKER,
-        define: { 'process.release.name': '"browser"' },
-    });
+    if (coiBuildEnabled()) {
+        console.log('[ ESBUILD ] duckdb-browser-coi.worker.js');
+        await esbuild.build({
+            entryPoints: ['./src/targets/duckdb-browser-coi.worker.ts'],
+            outfile: 'dist/duckdb-browser-coi.worker.js',
+            platform: 'browser',
+            format: 'iife',
+            globalName: 'duckdb',
+            target: TARGET_BROWSER,
+            bundle: true,
+            minify: true,
+            sourcemap: is_debug ? 'inline' : true,
+            external: EXTERNALS_WEBWORKER,
+            define: { 'process.release.name': '"browser"' },
+        });
 
-    console.log('[ ESBUILD ] duckdb-browser-coi.pthread.worker.js');
-    await esbuild.build({
-        entryPoints: ['./src/targets/duckdb-browser-coi.pthread.worker.ts'],
-        outfile: 'dist/duckdb-browser-coi.pthread.worker.js',
-        platform: 'browser',
-        format: 'iife',
-        target: TARGET_BROWSER,
-        bundle: true,
-        minify: true,
-        sourcemap: is_debug ? 'inline' : true,
-        external: EXTERNALS_WEBWORKER,
-        define: { 'process.release.name': '"browser"' },
-    });
+        console.log('[ ESBUILD ] duckdb-browser-coi.pthread.worker.js');
+        await esbuild.build({
+            entryPoints: ['./src/targets/duckdb-browser-coi.pthread.worker.ts'],
+            outfile: 'dist/duckdb-browser-coi.pthread.worker.js',
+            platform: 'browser',
+            format: 'iife',
+            target: TARGET_BROWSER,
+            bundle: true,
+            minify: true,
+            sourcemap: is_debug ? 'inline' : true,
+            external: EXTERNALS_WEBWORKER,
+            define: { 'process.release.name': '"browser"' },
+        });
+    }
 
     // -------------------------------
     // Node bundles
@@ -251,6 +270,7 @@ fs.copyFile(path.resolve(src, 'bindings', 'duckdb-coi.wasm'), path.resolve(dist,
         minify: true,
         sourcemap: is_debug ? 'inline' : true,
         external: EXTERNALS_NODE,
+        plugins: pluginConfig,
     });
 
     console.log('[ ESBUILD ] duckdb-node-mvp.worker.cjs');
@@ -266,18 +286,20 @@ fs.copyFile(path.resolve(src, 'bindings', 'duckdb-coi.wasm'), path.resolve(dist,
         external: EXTERNALS_NODE,
     });
 
-    console.log('[ ESBUILD ] duckdb-node-eh.worker.cjs');
-    await esbuild.build({
-        entryPoints: ['./src/targets/duckdb-node-eh.worker.ts'],
-        outfile: 'dist/duckdb-node-eh.worker.cjs',
-        platform: 'node',
-        format: 'cjs',
-        target: TARGET_NODE,
-        bundle: true,
-        minify: true,
-        sourcemap: is_debug ? 'inline' : true,
-        external: EXTERNALS_NODE,
-    });
+    if (ehBuildEnabled()) {
+        console.log('[ ESBUILD ] duckdb-node-eh.worker.cjs');
+        await esbuild.build({
+            entryPoints: ['./src/targets/duckdb-node-eh.worker.ts'],
+            outfile: 'dist/duckdb-node-eh.worker.cjs',
+            platform: 'node',
+            format: 'cjs',
+            target: TARGET_NODE,
+            bundle: true,
+            minify: true,
+            sourcemap: is_debug ? 'inline' : true,
+            external: EXTERNALS_NODE,
+        });
+    }
 
     // -------------------------------
     // Test bundles
@@ -293,6 +315,7 @@ fs.copyFile(path.resolve(src, 'bindings', 'duckdb-coi.wasm'), path.resolve(dist,
         bundle: true,
         sourcemap: is_debug ? 'inline' : true,
         external: EXTERNALS_TEST_BROWSER,
+        plugins: pluginConfig,
     });
 
     console.log('[ ESBUILD ] tests-node.cjs');
@@ -305,8 +328,10 @@ fs.copyFile(path.resolve(src, 'bindings', 'duckdb-coi.wasm'), path.resolve(dist,
         bundle: true,
         minify: false,
         sourcemap: is_debug ? 'inline' : true,
-        // web-worker polyfill needs to be excluded from bundling due to their dynamic require messing with bundled modules
+        // web-worker polyfill needs to be excluded from
+        // bundling due to their dynamic require messing with bundled modules
         external: [...EXTERNALS_NODE, 'web-worker'],
+        plugins: pluginConfig,
     });
 
     // -------------------------------
diff --git a/packages/duckdb-wasm/package.json b/packages/duckdb-wasm/package.json
index d46250d39..070b6a773 100644
--- a/packages/duckdb-wasm/package.json
+++ b/packages/duckdb-wasm/package.json
@@ -32,6 +32,8 @@
         "@typescript-eslint/parser": "^6.7.3",
         "esbuild": "^0.19.5",
         "eslint": "^8.50.0",
+        "esbuild-ifdef": "^0.2.0",
+        "esbuild-plugin-ifdef": "^1.0.1",
         "eslint-plugin-jasmine": "^4.1.3",
         "eslint-plugin-react": "^7.33.2",
         "fast-glob": "^3.3.1",
diff --git a/packages/duckdb-wasm/src/targets/duckdb-browser-blocking.ts b/packages/duckdb-wasm/src/targets/duckdb-browser-blocking.ts
index a82e59e51..8d660377f 100644
--- a/packages/duckdb-wasm/src/targets/duckdb-browser-blocking.ts
+++ b/packages/duckdb-wasm/src/targets/duckdb-browser-blocking.ts
@@ -11,7 +11,9 @@ import { Logger } from '../log';
 import { DuckDBRuntime, DuckDBBindings } from '../bindings';
 import { DuckDBBundles, getPlatformFeatures } from '../platform';
 import { DuckDB as DuckDBMVP } from '../bindings/bindings_browser_mvp';
+//#ifdef EH_BUILD_ENABLED
 import { DuckDB as DuckDBNext } from '../bindings/bindings_browser_eh';
+//#endif
 
 export async function createDuckDB(
     bundles: DuckDBBundles,
@@ -19,10 +21,12 @@ export async function createDuckDB(
     runtime: DuckDBRuntime,
 ): Promise<DuckDBBindings> {
     const platform = await getPlatformFeatures();
+//#ifdef EH_BUILD_ENABLED
     if (platform.wasmExceptions) {
         if (bundles.eh) {
             return new DuckDBNext(logger, runtime, bundles.eh!.mainModule);
         }
     }
+//#endif
     return new DuckDBMVP(logger, runtime, bundles.mvp.mainModule);
 }
diff --git a/packages/duckdb-wasm/src/targets/duckdb-node-blocking.ts b/packages/duckdb-wasm/src/targets/duckdb-node-blocking.ts
index d31ec1fe9..9b759382c 100644
--- a/packages/duckdb-wasm/src/targets/duckdb-node-blocking.ts
+++ b/packages/duckdb-wasm/src/targets/duckdb-node-blocking.ts
@@ -12,7 +12,9 @@ import { DuckDBRuntime } from '../bindings';
 import { DuckDBNodeBindings } from '../bindings/bindings_node_base';
 import { DuckDBBundles, getPlatformFeatures } from '../platform';
 import { DuckDB as DuckDBMVP } from '../bindings/bindings_node_mvp';
+//#ifdef EH_BUILD_ENABLED
 import { DuckDB as DuckDBNext } from '../bindings/bindings_node_eh';
+//#endif
 
 export async function createDuckDB(
     bundles: DuckDBBundles,
@@ -20,10 +22,12 @@ export async function createDuckDB(
     runtime: DuckDBRuntime,
 ): Promise<DuckDBNodeBindings> {
     const platform = await getPlatformFeatures();
+//#ifdef EH_BUILD_ENABLED
     if (platform.wasmExceptions) {
         if (bundles.eh) {
             return new DuckDBNext(logger, runtime, bundles.eh!.mainModule);
         }
     }
+//#endif
     return new DuckDBMVP(logger, runtime, bundles.mvp.mainModule);
 }
diff --git a/yarn.lock b/yarn.lock
index d0d2cb8c9..001e2d989 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -456,20 +456,6 @@
   resolved "https://registry.yarnpkg.com/@discoveryjs/json-ext/-/json-ext-0.5.7.tgz#1d572bfbbe14b7704e0ba0f39b74815b84870d70"
   integrity sha512-dBVuXR082gk3jsFp7Rd/JI4kytwGHecnCoTtXFb7DB6CNHp4rg5k1bhg0nWdLGLnOV71lmDzGQaLMy8iPLY0pw==
 
-"@duckdb/duckdb-wasm-shell@file:packages/duckdb-wasm-shell":
-  version "1.11.0"
-  dependencies:
-    "@duckdb/duckdb-wasm" "file:packages/duckdb-wasm"
-    xterm "^5.1.0"
-    xterm-addon-fit "^0.7.0"
-    xterm-addon-web-links "^0.9.0"
-    xterm-addon-webgl "^0.16.0"
-
-"@duckdb/duckdb-wasm@file:packages/duckdb-wasm":
-  version "1.11.0"
-  dependencies:
-    apache-arrow "^13.0.0"
-
 "@emotion/is-prop-valid@^0.8.2":
   version "0.8.8"
   resolved "https://registry.yarnpkg.com/@emotion/is-prop-valid/-/is-prop-valid-0.8.8.tgz#db28b1c4368a259b60a97311d6a952d4fd01ac1a"
@@ -3101,6 +3087,17 @@ es6-error@^4.0.1:
   resolved "https://registry.yarnpkg.com/es6-error/-/es6-error-4.1.1.tgz#9e3af407459deed47e9a91f9b885a84eb05c561d"
   integrity sha512-Um/+FxMr9CISWh0bi5Zv0iOD+4cFh5qLeks1qhAopKVAJw3drgKbKySikp7wGhDL0HPeaja0P5ULZrxLkniUVg==
 
+esbuild-ifdef@^0.2.0:
+  version "0.2.0"
+  resolved "https://registry.yarnpkg.com/esbuild-ifdef/-/esbuild-ifdef-0.2.0.tgz#7f6163a0358f8d747935009fb38d042514668602"
+  integrity sha512-1+QJyEI3hIN5SY56MBgnfOQWqNTjfRBbkGKyTHvL44A+Q/NlKwJ79w1nZcIjHhvouM7ArngK99yiMjd6G3iC6A==
+
+esbuild-plugin-ifdef@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/esbuild-plugin-ifdef/-/esbuild-plugin-ifdef-1.0.1.tgz#64f281879725231b6d1493b0f38ab1ae1ac80313"
+  integrity sha512-dn1sf+WGIUBp4kxN+rJRYIXrmGTwRLyhWASmhl8IKKKPfIlWFE8hloAVnI6mM5jPF3+abDvkndYe+RZDFXItbA==
+
+
 esbuild@^0.19.5:
   version "0.19.5"
   resolved "https://registry.yarnpkg.com/esbuild/-/esbuild-0.19.5.tgz#53a0e19dfbf61ba6c827d51a80813cf071239a8c"
@@ -4144,6 +4141,13 @@ ieee754@^1.1.13:
   resolved "https://registry.yarnpkg.com/ieee754/-/ieee754-1.2.1.tgz#8eb7a10a63fff25d15a57b001586d177d1b0d352"
   integrity sha512-dcyqhDvX1C46lXZcVqCpK+FtMRQVdIMN6/Df5js2zouUsqG7I6sFxitIC+7KYK29KdXOLHdu9zL4sFnoVQnqaA==
 
+ifdef-loader@^2.3.2:
+  version "2.3.2"
+  resolved "https://registry.yarnpkg.com/ifdef-loader/-/ifdef-loader-2.3.2.tgz#d08972f53c32e90dce6722b6efb9b3a91717cfef"
+  integrity sha512-kH9bHPrfIFxLpq3XEruJqSlHXch2nOljKIDRS/6MU5LDZTyHeaSWVf04wNYX+8RT+NDmeS8Vm5HwZ7akkXo8ig==
+  dependencies:
+    loader-utils "^1.1.0"
+
 ignore@^5.2.0, ignore@^5.2.4:
   version "5.2.4"
   resolved "https://registry.yarnpkg.com/ignore/-/ignore-5.2.4.tgz#a291c0c6178ff1b960befe47fcdec301674a6324"
@@ -4765,6 +4769,13 @@ json-stable-stringify-without-jsonify@^1.0.1:
   resolved "https://registry.yarnpkg.com/json-stable-stringify-without-jsonify/-/json-stable-stringify-without-jsonify-1.0.1.tgz#9db7b59496ad3f3cfef30a75142d2d930ad72651"
   integrity sha1-nbe1lJatPzz+8wp1FC0tkwrXJlE=
 
+json5@^1.0.1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/json5/-/json5-1.0.2.tgz#63d98d60f21b313b77c4d6da18bfa69d80e1d593"
+  integrity sha512-g1MWMLBiz8FKi1e4w0UyVL3w+iJceWAFBAaBnnGKOpNa5f8TLktkbre1+s6oICydWAm+HRUGTmI+//xv2hvXYA==
+  dependencies:
+    minimist "^1.2.0"
+
 json5@^2.1.2:
   version "2.2.0"
   resolved "https://registry.yarnpkg.com/json5/-/json5-2.2.0.tgz#2dfefe720c6ba525d9ebd909950f0515316c89a3"
@@ -5012,6 +5023,15 @@ loader-runner@^4.2.0:
   resolved "https://registry.yarnpkg.com/loader-runner/-/loader-runner-4.2.0.tgz#d7022380d66d14c5fb1d496b89864ebcfd478384"
   integrity sha512-92+huvxMvYlMzMt0iIOukcwYBFpkYJdpl2xsZ7LrlayO7E8SOv+JJUEK17B/dJIHAOLMfh2dZZ/Y18WgmGtYNw==
 
+loader-utils@^1.1.0:
+  version "1.4.2"
+  resolved "https://registry.yarnpkg.com/loader-utils/-/loader-utils-1.4.2.tgz#29a957f3a63973883eb684f10ffd3d151fec01a3"
+  integrity sha512-I5d00Pd/jwMD2QCduo657+YM/6L3KZu++pmX9VFncxaxvHcru9jx1lBaFft+r4Mt2jK0Yhp41XlRAihzPxHNCg==
+  dependencies:
+    big.js "^5.2.2"
+    emojis-list "^3.0.0"
+    json5 "^1.0.1"
+
 loader-utils@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/loader-utils/-/loader-utils-2.0.0.tgz#e4cace5b816d425a166b5f097e10cd12b36064b0"
@@ -5283,6 +5303,11 @@ minimatch@^9.0.1, minimatch@^9.0.3:
   dependencies:
     brace-expansion "^2.0.1"
 
+minimist@^1.2.0:
+  version "1.2.8"
+  resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.8.tgz#c1a464e7693302e082a075cee0c057741ac4772c"
+  integrity sha512-2yyAR8qBkN3YuheJanUpWC5U3bb5osDywNB8RzDVlDwDHbocAJveqqj1u8+SVD7jkWT4yvsHCpWqqWqAxb0zCA==
+
 minimist@^1.2.5, minimist@^1.2.6:
   version "1.2.6"
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.6.tgz#8637a5b759ea0d6e98702cfb3a9283323c93af44"