diff --git a/docs/docs/stdlib.md b/docs/docs/stdlib.md
index 6dd83bc..1e383e8 100644
--- a/docs/docs/stdlib.md
+++ b/docs/docs/stdlib.md
@@ -33,7 +33,7 @@ Returns `quickjs-ng/<version>`.
 
 Shorthand for `std.gc()`.
 
-## `bjson` module
+## `qjs:bjson` module
 
 ### `bjson.write(obj, [flags])`
 
@@ -58,7 +58,7 @@ Supported flags:
 - `READ_OBJ_REFERENCE`: allow de-serializing object references
 - `READ_OBJ_SAB`: allow de-serializing SharedArrayBuffer instances
 
-## `os` module
+## `qjs:os` module
 
 The `os` module provides Operating System specific functions:
 
@@ -323,7 +323,7 @@ The worker instances have the following properties:
   received message. The thread is not terminated if there is at least
   one non `null` `onmessage` handler.
 
-## `std` module
+## `qjs:std` module
 
 The `std` module provides wrappers to libc (`stdlib.h` and `stdio.h`) and a few other utilities.
 
diff --git a/examples/test_fib.js b/examples/test_fib.js
index 4bdf9dc..f22c576 100644
--- a/examples/test_fib.js
+++ b/examples/test_fib.js
@@ -1,5 +1,5 @@
 /* example of JS module importing a C module */
-import * as os from "os";
+import * as os from "qjs:os";
 
 const isWin = os.platform === 'win32';
 const { fib } = await import(`./fib.${isWin ? 'dll' : 'so'}`);
diff --git a/examples/test_point.js b/examples/test_point.js
index 7400420..1e0fafa 100644
--- a/examples/test_point.js
+++ b/examples/test_point.js
@@ -1,5 +1,5 @@
 /* example of JS module importing a C module */
-import * as os from "os";
+import * as os from "qjs:os";
 
 const isWin = os.platform === 'win32';
 const { Point } = await import(`./point.${isWin ? 'dll' : 'so'}`);
diff --git a/gen/repl.c b/gen/repl.c
index 5024e94..f92b09d 100644
Binary files a/gen/repl.c and b/gen/repl.c differ
diff --git a/gen/test_fib.c b/gen/test_fib.c
index 097cd76..579f9d0 100644
Binary files a/gen/test_fib.c and b/gen/test_fib.c differ
diff --git a/qjs.c b/qjs.c
index 5631543..30d4577 100644
--- a/qjs.c
+++ b/qjs.c
@@ -164,9 +164,9 @@ static JSContext *JS_NewCustomContext(JSRuntime *rt)
     if (!ctx)
         return NULL;
     /* system modules */
-    js_init_module_std(ctx, "std");
-    js_init_module_os(ctx, "os");
-    js_init_module_bjson(ctx, "bjson");
+    js_init_module_std(ctx, "qjs:std");
+    js_init_module_os(ctx, "qjs:os");
+    js_init_module_bjson(ctx, "qjs:bjson");
 
     JSValue global = JS_GetGlobalObject(ctx);
     JS_SetPropertyFunctionList(ctx, global, global_obj, countof(global_obj));
diff --git a/qjsc.c b/qjsc.c
index 1ef26ee..8e0b58b 100644
--- a/qjsc.c
+++ b/qjsc.c
@@ -375,7 +375,11 @@ int main(int argc, char **argv)
     stack_size = 0;
     memset(&dynamic_module_list, 0, sizeof(dynamic_module_list));
 
+    
     /* add system modules */
+    namelist_add(&cmodule_list, "qjs:std", "std", 0);
+    namelist_add(&cmodule_list, "qjs:os", "os", 0);
+    namelist_add(&cmodule_list, "qjs:bjson", "bjson", 0);
     namelist_add(&cmodule_list, "std", "std", 0);
     namelist_add(&cmodule_list, "os", "os", 0);
     namelist_add(&cmodule_list, "bjson", "bjson", 0);
diff --git a/quickjs.c b/quickjs.c
index c79b509..da72553 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -26267,6 +26267,16 @@ static char *js_default_module_normalize_name(JSContext *ctx,
     int len;
 
     if (name[0] != '.') {
+        /* Backwards compatibility for stdlib rename. */
+        static const char names[] = "qjs:bjson\0qjs:std\0qjs:os";
+        for (const char *p = names; p < endof(names); p += 1 + strlen(p)) {
+            if (!strcmp(name, p+4)) {
+#ifndef NDEBUG
+                printf("WARN: Standard library modules should be prefixed with `qjs:`. Example: %s\n", p);
+#endif
+                return js_strdup(ctx, p);
+            }
+        }
         /* if no initial dot, the module name is not modified */
         return js_strdup(ctx, name);
     }
diff --git a/repl.js b/repl.js
index 78f354e..00dd52b 100644
--- a/repl.js
+++ b/repl.js
@@ -22,9 +22,9 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-import * as std from "std";
-import * as os from "os";
-import * as bjson from "bjson";
+import * as std from "qjs:std";
+import * as os from "qjs:os";
+import * as bjson from "qjs:bjson";
 
 (function(g) {
     /* add 'bjson', 'os' and 'std' bindings */
diff --git a/run-test262.c b/run-test262.c
index 9f44ac4..3c88496 100644
--- a/run-test262.c
+++ b/run-test262.c
@@ -1695,9 +1695,9 @@ JSContext *JS_NewCustomContext(JSRuntime *rt)
 
     ctx = JS_NewContext(rt);
     if (ctx && local) {
-        js_init_module_std(ctx, "std");
-        js_init_module_os(ctx, "os");
-        js_init_module_bjson(ctx, "bjson");
+        js_init_module_std(ctx, "qjs:std");
+        js_init_module_os(ctx, "qjs:os");
+        js_init_module_bjson(ctx, "qjs:bjson");
     }
     return ctx;
 }
diff --git a/tests/detect_module/4.js b/tests/detect_module/4.js
index 3ee1df7..5713f31 100644
--- a/tests/detect_module/4.js
+++ b/tests/detect_module/4.js
@@ -1,3 +1,3 @@
 // imports should classify it as a module, even when not at the top
 os.now()
-import * as os from "os"
+import * as os from "qjs:os"
diff --git a/tests/microbench.js b/tests/microbench.js
index c8cb4c7..5560c24 100644
--- a/tests/microbench.js
+++ b/tests/microbench.js
@@ -22,8 +22,8 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-import * as std from "std";
-import * as os from "os";
+import * as std from "qjs:std";
+import * as os from "qjs:os";
 
 function pad(str, n) {
     str += "";
diff --git a/tests/test_bjson.js b/tests/test_bjson.js
index a957cee..4976015 100644
--- a/tests/test_bjson.js
+++ b/tests/test_bjson.js
@@ -1,5 +1,5 @@
-import * as std from "std";
-import * as bjson from "bjson";
+import * as std from "qjs:std";
+import * as bjson from "qjs:bjson";
 import { assert } from "./assert.js";
 
 function base64decode(s) {
diff --git a/tests/test_builtin.js b/tests/test_builtin.js
index 0dbe243..4c29503 100644
--- a/tests/test_builtin.js
+++ b/tests/test_builtin.js
@@ -1,4 +1,4 @@
-import * as os from "os";
+import * as os from "qjs:os";
 import { assert, assertThrows } from "./assert.js";
 
 // Keep this at the top; it tests source positions.
diff --git a/tests/test_std.js b/tests/test_std.js
index b9ea6e2..0f70c6d 100644
--- a/tests/test_std.js
+++ b/tests/test_std.js
@@ -1,5 +1,5 @@
-import * as std from "std";
-import * as os from "os";
+import * as std from "qjs:std";
+import * as os from "qjs:os";
 import { assert } from  "./assert.js";
 
 const isWin = os.platform === 'win32';
diff --git a/tests/test_worker.js b/tests/test_worker.js
index bd0d0b9..8309c18 100644
--- a/tests/test_worker.js
+++ b/tests/test_worker.js
@@ -1,4 +1,4 @@
-import * as os from "os";
+import * as os from "qjs:os";
 import { assert } from "./assert.js";
 
 var worker;
diff --git a/tests/test_worker_module.js b/tests/test_worker_module.js
index 91a83f6..7280c69 100644
--- a/tests/test_worker_module.js
+++ b/tests/test_worker_module.js
@@ -1,6 +1,5 @@
 /* Worker code for test_worker.js */
-import * as std from "std";
-import * as os from "os";
+import * as os from "qjs:os";
 
 var parent = os.Worker.parent;