diff --git a/cstruct/__init__.py b/cstruct/__init__.py
index 2ca18bb..a97062c 100644
--- a/cstruct/__init__.py
+++ b/cstruct/__init__.py
@@ -142,8 +142,8 @@ def print_info(self):
     'uint16':               'H',
     'int32':                'i',
     'uint32':               'I',
-    'int64':                'l',
-    'uint64':               'L',
+    'int64':                'q',
+    'uint64':               'Q',
 }
 
 STRUCTS = {