diff --git a/Makefile.common b/Makefile.common
index 9db64a4a2..7b0e6e32c 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -118,7 +118,7 @@ ifeq ($(GOHOSTARCH),amd64)
         endif
 endif
 
-test-flags += "-timeout 20m"
+test-flags += -timeout 20m
 
 # This rule is used to forward a target like "build" to "common-build".  This
 # allows a new "build" target to be defined in a Makefile which includes this