diff --git a/meta/recipes-support/nettle/nettle_3.4.1.bb b/meta/recipes-support/nettle/nettle_3.4.1.bb
index dd49c30c84..8375fcf2df 100644
--- a/meta/recipes-support/nettle/nettle_3.4.1.bb
+++ b/meta/recipes-support/nettle/nettle_3.4.1.bb
@@ -30,7 +30,7 @@ inherit autotools ptest multilib_header
 EXTRA_AUTORECONF += "--exclude=aclocal"
 
 EXTRA_OECONF = "--disable-openssl"
-CFLAGS_append = " -std=c99"
+CFLAGS_append = " -std=gnu99"
 
 do_compile_ptest() {
         oe_runmake buildtest