diff --git a/package/libtasn1/libtasn1.mk b/package/libtasn1/libtasn1.mk
index 9b8260ab48..d5a6c69965 100644
--- a/package/libtasn1/libtasn1.mk
+++ b/package/libtasn1/libtasn1.mk
@@ -17,4 +17,6 @@ LIBTASN1_AUTORECONF = YES
 # 'missing' fallback logic botched so disable it completely
 LIBTASN1_CONF_ENV = MAKEINFO="true"
 
+LIBTASN1_CONF_OPTS = CFLAGS="$(TARGET_CFLAGS) -std=gnu99"
+
 $(eval $(autotools-package))