diff --git a/lib/include/stdio.pre.pike b/lib/include/stdio.pre.pike
index 01ca085b84f470f086c088f3f8e56c1ffd52f183..5640225c563ed10ee591edce9060b5a1cbf1922a 100644
--- a/lib/include/stdio.pre.pike
+++ b/lib/include/stdio.pre.pike
@@ -199,9 +199,9 @@ int file_size(string s)
 void perror(string s)
 {
 #if efun(strerror)
-  stderr->write(s+": "+strerror(errno())+"\n");
+  stderr->write(s+": "+strerror(predef::errno())+"\n");
 #else
-  stderr->write(s+": errno: "+errno()+"\n");
+  stderr->write(s+": errno: "+predef::errno()+"\n");
 #endif
 }