diff --git a/lib/modules/Process.pmod b/lib/modules/Process.pmod
index 1ba4be5201801559864e1b9a6f17ac20bd0c10be..1cf7c5e34cc622aa64f5fe08d1784b26fe0c8465 100644
--- a/lib/modules/Process.pmod
+++ b/lib/modules/Process.pmod
@@ -2,6 +2,10 @@
 
 import Stdio;
 
+#if !constant(strerror)
+#define strerror(X) ("errno="+X)
+#endif
+
 program create_process = _static_modules.Builtin()->create_process;
 
 int exec(string file,string ... foo)