diff --git a/certs/Makefile b/certs/Makefile
index 799ad7b9e68a..f15eca11ea1e 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -47,7 +47,7 @@ keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_ECDSA) := -newkey ec -pkeyopt ec_paramgen_c
 quiet_cmd_gen_key = GENKEY  $@
       cmd_gen_key = openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
 		-batch -x509 -config $< \
-		-outform PEM -out $@ -keyout $@ $(keytype-y) 2>&1
+		-outform PEM -out $@ -keyout $@ $(keytype-y) 2> /dev/null
 
 $(obj)/signing_key.pem: $(obj)/x509.genkey FORCE
 	$(call if_changed,gen_key)