--- a/src/org/python/core/imp.java
+++ b/src/org/python/core/imp.java
@@ -228,7 +228,7 @@
         }
         if (testing && mtime != NO_MTIME) {
             long time = ar.getMTime();
-            if (mtime != time) {
+            if (mtime < time) {
                 return null;
             }
         }