diff --git a/common.mk b/common.mk
index 7939883..a3b3e98 100644
--- a/common.mk
+++ b/common.mk
@@ -282,7 +282,7 @@
 COMMON_CFLAGS := -Wall -Werror -fno-strict-aliasing -O1 -Wformat=2
 CXXFLAGS += $(COMMON_CFLAGS) $(COMMON_CFLAGS-$(CXXDRIVER))
 CFLAGS += $(COMMON_CFLAGS) $(COMMON_CFLAGS-$(CDRIVER))
-CPPFLAGS += -D_FORTIFY_SOURCE=2
+CPPFLAGS += -D_FORTIFY_SOURCE=3
 
 
 ifeq ($(MODE),opt)