Index: rw/readWritePS.c
--- rw/readWritePS.c.orig
+++ rw/readWritePS.c
@@ -383,7 +383,7 @@ ReadPS(char *file)
     fclose(fp);
 
     type_doc = TestPS(file);
-    if (!type_doc) return; /* should not happen anyway ... */
+    if (!type_doc) return NULL; /* should not happen anyway ... */
 
     strncpy(rad, file, 256),
     rad[256] = '\0';