diff --git a/src/lib.rs b/src/lib.rs
index 51ccfdca..30afd3e3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -53,6 +53,7 @@ impl Build {
 
     fn cmd_make(&self) -> Command {
         let host = &self.host.as_ref().expect("HOST dir not set")[..];
+        let target = &self.target.as_ref().expect("TARGET dir not set")[..];
         if host.contains("dragonfly")
             || host.contains("freebsd")
             || host.contains("openbsd")
@@ -61,7 +62,13 @@ impl Build {
         {
             Command::new("gmake")
         } else {
-            Command::new("make")
+            if target.contains("wasm") {
+                let mut cmd = Command::new("wasimake");
+
+                std::mem::replace(cmd.arg("make"), Command::new("wasimake"))
+            } else {
+                Command::new("make")
+            }
         }
     }
 
@@ -129,10 +136,17 @@ impl Build {
         let inner_dir = build_dir.join("src");
         fs::create_dir_all(&inner_dir).unwrap();
         cp_r(&source_dir(), &inner_dir);
+        let mut program = String::new();
 
-        let perl_program =
-            env::var("OPENSSL_SRC_PERL").unwrap_or(env::var("PERL").unwrap_or("perl".to_string()));
-        let mut configure = Command::new(perl_program);
+        // use wasiconfigure when targeting wasm
+        if target.contains("wasm") {
+            program = String::from("wasiconfigure");
+        } else {
+            program = env::var("OPENSSL_SRC_PERL")
+                .unwrap_or(env::var("PERL").unwrap_or("perl".to_string()));
+        }
+
+        let mut configure = Command::new(program);
         configure.arg("./Configure");
         if host.contains("pc-windows-gnu") {
             configure.arg(&format!("--prefix={}", sanitize_sh(&install_dir)));
@@ -155,7 +169,7 @@ impl Build {
             // Avoid multilib-postfix for build targets that specify it
             .arg("--libdir=lib");
 
-        if cfg!(not(feature = "legacy")) {
+        if cfg!(not(feature = "legacy")) && !target.contains("wasm") {
             configure.arg("no-legacy");
         }
 
@@ -203,6 +217,21 @@ impl Build {
             configure.arg("no-stdio");
         }
 
+        if target.contains("wasm") {
+            // -no-threads we dont have thread support in WASI
+            configure.arg("no-threads");
+            // -no-sock we dont have sockets in WASI
+            configure.arg("no-sock");
+            configure.arg("no-afalgeng");
+            configure.arg("-DOPENSSL_SYS_NETWARE");
+            configure.arg("-DSIG_DFL=0");
+            configure.arg("-DSIG_IGN=0");
+            configure.arg("-DHAVE_FORK=0");
+            configure.arg("-DOPENSSL_NO_AFALGENG=1");
+            // --with-rand-seed=getrandom (needed to force using getentropy because WASI has no /dev/random or getrandom)
+            configure.arg("--with-rand-seed=getrandom");
+        }
+
         if target.contains("msvc") {
             // On MSVC we need nasm.exe to compile the assembly files.
             // ASM compiling will be enabled if nasm.exe is installed, unless