Index: phobos/Makefile
--- phobos/Makefile.orig
+++ phobos/Makefile
@@ -143,7 +143,7 @@ ifneq ($(USE_IMPORTC),1)
 		CC_OUTFILEFLAG := /Fo
 		CFLAGS := /nologo /Zl /GS- $(if $(findstring $(BUILD),debug),/Z7,/O2)
 	else # Posix
-		CFLAGS := $(MODEL_FLAG) -fPIC -std=c11 $(if $(findstring $(BUILD),debug),-g,-O3)
+		CFLAGS += $(MODEL_FLAG) -fPIC -std=c11
 		ifeq (osx64,$(OS)$(MODEL))
 			CFLAGS += --target=x86_64-darwin-apple  # ARM cpu is not supported by dmd
 		endif
