diff --git a/runtime/js/unix.js b/runtime/js/unix.js
index b05ae747b2..75bbff9b0f 100644
--- a/runtime/js/unix.js
+++ b/runtime/js/unix.js
@@ -91,22 +91,6 @@ function caml_unix_startup() {}
 //Alias: win_cleanup
 function caml_unix_cleanup() {}
 
-//Provides: caml_sys_putenv (const, const)
-//Requires: caml_jsstring_of_string, jsoo_static_env
-function caml_sys_putenv(name, value) {
-  var name = caml_jsstring_of_string(name);
-  var value = caml_jsstring_of_string(value);
-  delete jsoo_static_env[name];
-  //nodejs env
-  var process = globalThis.process;
-  if (process && process.env) {
-    process.env[name] = value;
-    return 0;
-  }
-  if (!globalThis.jsoo_env) globalThis.jsoo_env = {};
-  globalThis.jsoo_env[name] = value;
-}
-
 //Provides: caml_unix_filedescr_of_fd const
 //Alias: win_handle_fd
 function caml_unix_filedescr_of_fd(x) {
diff --git a/runtime/wasm/runtime.js b/runtime/wasm/runtime.js
index 1f7c06a172..e88e837714 100644
--- a/runtime/wasm/runtime.js
+++ b/runtime/wasm/runtime.js
@@ -458,7 +458,6 @@
     argv: () => (isNode ? process.argv.slice(1) : ["a.out"]),
     on_windows: () => on_windows,
     getenv: (n) => (isNode ? process.env[n] : null),
-    putenv: (n, v) => process.env[n] = v,
     system: (c) => {
       var res = require("node:child_process").spawnSync(c, {
         shell: true,
diff --git a/runtime/wasm/unix.wat b/runtime/wasm/unix.wat
index 6450525d28..6bc49d2811 100644
--- a/runtime/wasm/unix.wat
+++ b/runtime/wasm/unix.wat
@@ -26,7 +26,6 @@
          (param i32) (param i32) (param i32) (param i32) (param i32) (param i32)
          (result f64)))
    (import "bindings" "utimes" (func $utimes (param anyref f64 f64)))
-   (import "bindings" "putenv" (func $putenv (param anyref anyref)))
    (import "bindings" "stat" (func $stat (param anyref i32) (result (ref eq))))
    (import "bindings" "lstat" (func $lstat (param anyref i32) (result (ref eq))))
    (import "bindings" "fstat"
@@ -338,12 +337,6 @@
             (call $caml_unix_error (pop externref) (ref.null eq))))
       (ref.i31 (i32.const 0)))
 
-   (func (export "caml_sys_putenv")
-      (param $name (ref eq)) (param $value (ref eq))
-      (call $putenv
-         (call $unwrap (call $caml_jsstring_of_string (local.get $name)))
-         (call $unwrap (call $caml_jsstring_of_string (local.get $value)))))
-
    (func (export "caml_alloc_stat")
       (param $large i32)
       (param $dev i32) (param $ino i32) (param $kind i32) (param $perm i32)