diff --git a/packages/build/src/plugins_core/functions/utils.js b/packages/build/src/plugins_core/functions/utils.js
index 138f011ece..912bd38769 100644
--- a/packages/build/src/plugins_core/functions/utils.js
+++ b/packages/build/src/plugins_core/functions/utils.js
@@ -16,7 +16,10 @@ const getRelativeFunctionMainFiles = async function ({ featureFlags, functionsSr
 
   const zisiFeatureFlags = getZisiFeatureFlags(featureFlags)
   const functions = await listFunctions(functionsSrc, { featureFlags: zisiFeatureFlags })
-  return functions.map(({ mainFile }) => relative(functionsSrc, mainFile))
+  const dedupedFunctions = new Map(functions.map((func) => [func.name, func]))
+  const relativeMainFiles = [...dedupedFunctions.values()].map(({ mainFile }) => relative(functionsSrc, mainFile))
+
+  return relativeMainFiles
 }
 
 export const getUserAndInternalFunctions = ({
diff --git a/packages/build/tests/core/fixtures/functions_duplicate_names/netlify/functions/function_one.js b/packages/build/tests/core/fixtures/functions_duplicate_names/netlify/functions/function_one.js
new file mode 100644
index 0000000000..767df32b9c
--- /dev/null
+++ b/packages/build/tests/core/fixtures/functions_duplicate_names/netlify/functions/function_one.js
@@ -0,0 +1 @@
+export const handler = () => true
diff --git a/packages/build/tests/core/fixtures/functions_duplicate_names/netlify/functions/function_one.ts b/packages/build/tests/core/fixtures/functions_duplicate_names/netlify/functions/function_one.ts
new file mode 100644
index 0000000000..767df32b9c
--- /dev/null
+++ b/packages/build/tests/core/fixtures/functions_duplicate_names/netlify/functions/function_one.ts
@@ -0,0 +1 @@
+export const handler = () => true
diff --git a/packages/build/tests/core/snapshots/tests.js.md b/packages/build/tests/core/snapshots/tests.js.md
index d245361e63..930cfdd061 100644
--- a/packages/build/tests/core/snapshots/tests.js.md
+++ b/packages/build/tests/core/snapshots/tests.js.md
@@ -2276,3 +2276,53 @@ Generated by [AVA](https://avajs.dev).
     ────────────────────────────────────────────────────────────────␊
     ␊
     (Netlify Build completed in 1ms)`
+
+## Removes duplicate function names from the list of processed functions
+
+> Snapshot 1
+
+    `␊
+    ────────────────────────────────────────────────────────────────␊
+      Netlify Build                                                 ␊
+    ────────────────────────────────────────────────────────────────␊
+    ␊
+    > Version␊
+      @netlify/build 1.0.0␊
+    ␊
+    > Flags␊
+      debug: true␊
+      repositoryRoot: packages/build/tests/core/fixtures/functions_duplicate_names␊
+      testOpts:␊
+        pluginsListUrl: test␊
+        silentLingeringProcesses: true␊
+    ␊
+    > Current directory␊
+      packages/build/tests/core/fixtures/functions_duplicate_names␊
+    ␊
+    > Config file␊
+      No config file was defined: using default values.␊
+    ␊
+    > Resolved config␊
+      build:␊
+        publish: packages/build/tests/core/fixtures/functions_duplicate_names␊
+        publishOrigin: default␊
+      functionsDirectory: packages/build/tests/core/fixtures/functions_duplicate_names/netlify/functions␊
+    ␊
+    > Context␊
+      production␊
+    ␊
+    ────────────────────────────────────────────────────────────────␊
+      1. Functions bundling                                         ␊
+    ────────────────────────────────────────────────────────────────␊
+    ␊
+    Packaging Functions from netlify/functions directory:␊
+     - function_one.js␊
+    ␊
+    ␊
+    (Functions bundling completed in 1ms)␊
+    ␊
+    ────────────────────────────────────────────────────────────────␊
+      Netlify Build Complete                                        ␊
+    ────────────────────────────────────────────────────────────────␊
+    ␊
+    (Netlify Build completed in 1ms)`
diff --git a/packages/build/tests/core/snapshots/tests.js.snap b/packages/build/tests/core/snapshots/tests.js.snap
index 3655f52ca4..abc45936ee 100644
Binary files a/packages/build/tests/core/snapshots/tests.js.snap and b/packages/build/tests/core/snapshots/tests.js.snap differ
diff --git a/packages/build/tests/core/tests.js b/packages/build/tests/core/tests.js
index fc983707f5..804a22778a 100644
--- a/packages/build/tests/core/tests.js
+++ b/packages/build/tests/core/tests.js
@@ -476,6 +476,10 @@ test('Bundles functions from the `.netlify/functions-internal` directory even if
   await runFixture(t, 'functions_user_missing')
 })
 
+test('Removes duplicate function names from the list of processed functions', async (t) => {
+  await runFixture(t, 'functions_duplicate_names')
+})
+
 test.serial('`rustTargetDirectory` is passed to zip-it-and-ship-it only when running in buildbot', async (t) => {
   const fixtureWithConfig = 'functions_config_1'
   const fixtureWithoutConfig = 'functions_internal_missing'