diff --git a/src/xspice/cmpp/pp_mod.c b/src/xspice/cmpp/pp_mod.c
index 847e2dc09..a890bd35e 100644
--- a/src/xspice/cmpp/pp_mod.c
+++ b/src/xspice/cmpp/pp_mod.c
@@ -133,7 +133,7 @@ void preprocess_mod_file (
       sprintf(error_str, "ERROR - Could not open input .mod file: %s",
 	      filename);
       print_error(error_str);
-      return;
+      exit(1);
    }
    
    current_filename = filename;
@@ -145,7 +145,7 @@ void preprocess_mod_file (
       sprintf(error_str, "ERROR - Could not open output .c: %s",
 	      output_filename);
       print_error(error_str);
-      return;
+      exit(1);
    }
    
    mod_ifs_table = &ifs_table;