diff --git a/OpenChange/MAPIStoreDraftsMessage.m b/OpenChange/MAPIStoreDraftsMessage.m
index cea145c2a..575a71c42 100644
--- a/OpenChange/MAPIStoreDraftsMessage.m
+++ b/OpenChange/MAPIStoreDraftsMessage.m
@@ -72,7 +72,7 @@ typedef void (*getMessageData_inMemCtx_) (MAPIStoreMessage *, SEL,
 - (uint64_t) objectVersion
 {
   return ([sogoObject isKindOfClass: SOGoDraftObjectK]
-          ? 0xffffffffffffffffLL
+          ? ULLONG_MAX 
           : [super objectVersion]);
 }
 
diff --git a/OpenChange/MAPIStoreFSMessage.m b/OpenChange/MAPIStoreFSMessage.m
index b3273350f..0432d8cbb 100644
--- a/OpenChange/MAPIStoreFSMessage.m
+++ b/OpenChange/MAPIStoreFSMessage.m
@@ -93,7 +93,7 @@ Class NSNumberK;
 
   return (version
           ? exchange_globcnt ([version unsignedLongLongValue])
-          : 0xffffffffffffffff);
+          : ULLONG_MAX);
 }
 
 - (int) getProperty: (void **) data
diff --git a/OpenChange/MAPIStoreGCSMessage.m b/OpenChange/MAPIStoreGCSMessage.m
index 0f7828adc..d3986be29 100644
--- a/OpenChange/MAPIStoreGCSMessage.m
+++ b/OpenChange/MAPIStoreGCSMessage.m
@@ -97,7 +97,7 @@
 
 - (uint64_t) objectVersion
 {
-  uint64_t version = 0xffffffffffffffffLL;
+  uint64_t version = ULLONG_MAX;
   NSNumber *changeNumber;
  
   if (!isNew)
diff --git a/OpenChange/MAPIStoreMailMessage.m b/OpenChange/MAPIStoreMailMessage.m
index 8f9ccac78..df2951831 100644
--- a/OpenChange/MAPIStoreMailMessage.m
+++ b/OpenChange/MAPIStoreMailMessage.m
@@ -354,7 +354,7 @@ _compareBodyKeysByPriority (id entry1, id entry2, void *data)
 
 - (uint64_t) objectVersion
 {
-  uint64_t version = 0xffffffffffffffffLL;
+  uint64_t version = ULLONG_MAX;
   NSNumber *uid, *changeNumber;
 
   uid = [(MAPIStoreMailFolder *)
diff --git a/OpenChange/MAPIStoreObject.m b/OpenChange/MAPIStoreObject.m
index d9f6e2820..24b3fee38 100644
--- a/OpenChange/MAPIStoreObject.m
+++ b/OpenChange/MAPIStoreObject.m
@@ -354,7 +354,7 @@ static Class NSExceptionK, MAPIStoreFolderK;
 {
   [self subclassResponsibility: _cmd];
 
-  return 0xffffffffffffffffLL;
+  return ULLONG_MAX;
 }
 
 - (int) getPrChangeKey: (void **) data
@@ -364,7 +364,7 @@ static Class NSExceptionK, MAPIStoreFolderK;
   uint64_t obVersion;
 
   obVersion = [self objectVersion];
-  if (obVersion == 0xffffffffffffffffLL)
+  if (obVersion == ULLONG_MAX)
     rc = MAPISTORE_ERR_NOT_FOUND;
   else
     rc = [self getReplicaKey: data fromGlobCnt: obVersion
@@ -380,7 +380,7 @@ static Class NSExceptionK, MAPIStoreFolderK;
   uint64_t obVersion;
 
   obVersion = [self objectVersion];
-  if (obVersion == 0xffffffffffffffffLL)
+  if (obVersion == ULLONG_MAX)
     rc = MAPISTORE_ERR_NOT_FOUND;
   else
     {
diff --git a/OpenChange/MAPIStorePermissionsTable.m b/OpenChange/MAPIStorePermissionsTable.m
index 48bab8ecb..04b2b3327 100644
--- a/OpenChange/MAPIStorePermissionsTable.m
+++ b/OpenChange/MAPIStorePermissionsTable.m
@@ -76,7 +76,7 @@
   uint64_t value = 0;
 
   if ([userId isEqualToString: @"anonymous"])
-    value = 0xffffffffffffffff;
+    value = ULLONG_MAX;
 
   *data = MAPILongLongValue (memCtx, value);