diff --git a/vlib/os/os_nix.c.v b/vlib/os/os_nix.c.v
index 1d3635abe1..648aa2affc 100644
--- a/vlib/os/os_nix.c.v
+++ b/vlib/os/os_nix.c.v
@@ -148,9 +148,9 @@ pub fn exec(cmd string) ?Result {
 	soutput := res.str()
 	// res.free()
 	exit_code := vpclose(f)
-	// if exit_code != 0 {
-	// return error(res)
-	// }
+	if exit_code == 127 {
+		return error_with_code(soutput, 127)
+	}
 	return Result{
 		exit_code: exit_code
 		output: soutput
diff --git a/vlib/os/os_windows.c.v b/vlib/os/os_windows.c.v
index e108952661..78f4f9bec6 100644
--- a/vlib/os/os_windows.c.v
+++ b/vlib/os/os_windows.c.v
@@ -241,13 +241,15 @@ pub fn exec(cmd string) ?Result {
 	create_pipe_ok := C.CreatePipe(voidptr(&child_stdout_read),
 		voidptr(&child_stdout_write), voidptr(&sa), 0)
 	if !create_pipe_ok {
-		error_msg := get_error_msg(int(C.GetLastError()))
-		return error('exec failed (CreatePipe): $error_msg')
+		error_num := int(C.GetLastError())
+		error_msg := get_error_msg(error_num)
+		return error_with_code('exec failed (CreatePipe): $error_msg', error_num)
 	}
 	set_handle_info_ok := C.SetHandleInformation(child_stdout_read, C.HANDLE_FLAG_INHERIT, 0)
 	if !set_handle_info_ok {
-		error_msg := get_error_msg(int(C.GetLastError()))
-		panic('exec failed (SetHandleInformation): $error_msg')
+		error_num := int(C.GetLastError())
+		error_msg := get_error_msg(error_num)
+		return error_with_code('exec failed (SetHandleInformation): $error_msg', error_num)
 	}
 
 	proc_info := ProcessInformation{}
@@ -267,7 +269,7 @@ pub fn exec(cmd string) ?Result {
 	if !create_process_ok {
 		error_num := int(C.GetLastError())
 		error_msg := get_error_msg(error_num)
-		return error('exec failed (CreateProcess) with code $error_num: $error_msg cmd: $cmd')
+		return error_with_code('exec failed (CreateProcess) with code $error_num: $error_msg cmd: $cmd', error_num)
 	}
 	C.CloseHandle(child_stdin)
 	C.CloseHandle(child_stdout_write)