diff --git a/layer/xcb_helpers.hpp b/layer/xcb_helpers.hpp
index f6ba1fc..7f2b8ca 100644
--- a/layer/xcb_helpers.hpp
+++ b/layer/xcb_helpers.hpp
@@ -139,6 +139,8 @@ namespace xcb {
           largestExtent = max(largestExtent, clippedRect.extent);
         }
       }
+
+      free(attributeReply);
     }
 
     free(reply);