diff --git a/ChangeLog b/ChangeLog
index a53adaf2f..22a41f97e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2012-03-12  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
+	* OpenChange/MAPIStoreTypes.m (_reverseCN): fixed used of ull
+	constants on 32 bit platforms.
+
 	* OpenChange/MAPIStoreGCSFolder.m (-componentQualifier): now
 	provided by the parent class itself.
 	(-contentComponentQualifier): new method that returns a qualifier
diff --git a/OpenChange/MAPIStoreTypes.m b/OpenChange/MAPIStoreTypes.m
index 01cd461ea..24dbac860 100644
--- a/OpenChange/MAPIStoreTypes.m
+++ b/OpenChange/MAPIStoreTypes.m
@@ -273,14 +273,14 @@ NSObjectFromValuePointer (enum MAPITAGS propTag, const void *data)
 static uint64_t
 _reverseCN (uint64_t cn)
 {
-  return ((cn & 0x00000000000000ffL) << 56
-          | (cn & 0x000000000000ff00L) << 40
-          | (cn & 0x0000000000ff0000L) << 24
-          | (cn & 0x00000000ff000000L) << 8
-          | (cn & 0x000000ff00000000L) >> 8
-          | (cn & 0x0000ff0000000000L) >> 24
-          | (cn & 0x00ff000000000000L) >> 40
-          | (cn & 0xff00000000000000L) >> 56);
+  return ((cn & UINT64_C (0x00000000000000ff)) << 56
+          | (cn & UINT64_C (0x000000000000ff00)) << 40
+          | (cn & UINT64_C (0x0000000000ff0000)) << 24
+          | (cn & UINT64_C (0x00000000ff000000)) << 8
+          | (cn & UINT64_C (0x000000ff00000000)) >> 8
+          | (cn & UINT64_C (0x0000ff0000000000)) >> 24
+          | (cn & UINT64_C (0x00ff000000000000)) >> 40
+          | (cn & UINT64_C (0xff00000000000000)) >> 56);
 }
 
 NSComparisonResult