--- a/common/autoconf/buildjdk-spec.gmk.in	Mon Dec 05 17:03:52 2016 -0800
+++ b/common/autoconf/buildjdk-spec.gmk.in	Tue Dec 06 11:38:05 2016 +0100
@@ -89,4 +89,10 @@
 # Control wether Hotspot builds gtest tests
 BUILD_GTEST := false
 
-JVM_VARIANTS := server
\ No newline at end of file
+JVM_VARIANTS := server
+
+# Some users still set EXTRA_*FLAGS on the make command line. Must
+# make sure to override that when building buildjdk.
+override EXTRA_CFLAGS :=
+override EXTRA_CXXFLAGS :=
+override EXTRA_LDFLAGS :=