diff --git a/ChangeLog b/ChangeLog
index 392c279e2..05342f5f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-09-30  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
+
+	* OpenChange/EOQualifier+MAPIFS.m (-[EOKeyValueQUalifier
+	_evaluateMAPIFSMessageProperties:): ensure finalKey is never nil
+	nor undefined.
+
 2011-09-27  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
 	* OpenChange/MAPIStoreFSMessage.m (-getPrChangeKey:inMemCtx:):
diff --git a/OpenChange/EOQualifier+MAPIFS.m b/OpenChange/EOQualifier+MAPIFS.m
index 470940ab0..cf5ba75a3 100644
--- a/OpenChange/EOQualifier+MAPIFS.m
+++ b/OpenChange/EOQualifier+MAPIFS.m
@@ -123,6 +123,9 @@ typedef BOOL (*EOComparator) (id, SEL, id);
       else
         finalKey = [NSNumber numberWithInt: [key intValue]];
     }
+  else
+    finalKey = @"";
+
   propValue = [properties objectForKey: finalKey];
   comparator = (EOComparator) [propValue methodForSelector: operator];