--- a/make/hotspot/lib/JvmFlags.gmk	2026-10-16 22:12:09.083534187 +0100
+++ b/make/hotspot/lib/JvmFlags.gmk	2026-10-16 22:12:09.083819831 +0100
@@ -90,7 +90,7 @@
     $(JVM_CFLAGS_TARGET_DEFINES) \
     $(JVM_CFLAGS_FEATURES) \
     $(JVM_CFLAGS_INCLUDES) \
-    $(EXTRA_CFLAGS) \
+    $(EXTRA_CXXFLAGS) \
     #
 
 # -DDONT_USE_PRECOMPILED_HEADER will exclude all includes in precompiled.hpp.