diff --git a/Makefile b/Makefile
index f2128cc25d..224f6ada29 100644
--- a/Makefile
+++ b/Makefile
@@ -117,7 +117,7 @@ O_LEVEL ?= g
 else
 O_LEVEL ?= 2
 endif
-CPPFLAGS := $(INCLUDE_CPP_ARGS) -Wno-trigraphs -DMODERN=1 -DTESTING=$(TEST)
+CPPFLAGS := $(INCLUDE_CPP_ARGS) -Wno-trigraphs -DMODERN=1 -DTESTING=$(TEST) -std=gnu17
 ARMCC := $(PREFIX)gcc
 PATH_ARMCC := PATH="$(PATH)" $(ARMCC)
 CC1 := $(shell $(PATH_ARMCC) --print-prog-name=cc1) -quiet