diff --git a/Lib/test/string_tests.py b/Lib/test/string_tests.py
index c2e0875..8962c1f 100644
--- a/Lib/test/string_tests.py
+++ b/Lib/test/string_tests.py
@@ -115,7 +115,8 @@
         self.checkequal(2, 'aaa', 'count', 'a', 0, -1)
         self.checkequal(0, 'aaa', 'count', 'a', 0, -10)
         self.checkequal(3, 'aaa', 'count', '', 1)
-        self.checkequal(1, 'aaa', 'count', '', 10)
+        self.checkequal(1, 'aaa', 'count', '', 3)
+        self.checkequal(0, 'aaa', 'count', '', 10)
         self.checkequal(2, 'aaa', 'count', '', -1)
         self.checkequal(4, 'aaa', 'count', '', -10)
 
diff --git a/Objects/stringlib/count.h b/Objects/stringlib/count.h
index 84a852f..367a15c 100644
--- a/Objects/stringlib/count.h
+++ b/Objects/stringlib/count.h
@@ -15,7 +15,7 @@
 
     if (sub_len == 0) {
         if (str_len < 0)
-            return 1; /* start >= len(str) */
+            return 0; /* start > len(str) */
         return str_len + 1;
     }