diff --git a/Makefile b/Makefile
index 94a8721ad..5221141a3 100644
--- a/Makefile
+++ b/Makefile
@@ -61,6 +61,7 @@ grpc-hs: grpc-hs-deps
 		--includeDir . \
 		--proto HStream/Gossip/HStreamGossip.proto \
 		--out ../gen-hs)
+	(find common/api/gen-hs/ -type f -name '*.hs' -exec sed -i '1i{-# OPTIONS_GHC -w #-}\n' {} \;)
 
 grpc-cpp:
 	(cd common/api && mkdir -p cpp/gen && \