diff --git a/xcode/OLMKit/OLMInboundGroupSession.m b/xcode/OLMKit/OLMInboundGroupSession.m
index 3ef02e8..08459ca 100644
--- a/xcode/OLMKit/OLMInboundGroupSession.m
+++ b/xcode/OLMKit/OLMInboundGroupSession.m
@@ -204,6 +204,7 @@
         return nil;
     }
     NSString *keyString = [[NSString alloc] initWithData:key encoding:NSUTF8StringEncoding];
+    [key resetBytesInRange:NSMakeRange(0, key.length)];
     return keyString;
 }