diff --git a/libs/libtasn1/Makefile b/libs/libtasn1/Makefile
index d471c6ecf..e5bf554fe 100644
--- a/libs/libtasn1/Makefile
+++ b/libs/libtasn1/Makefile
@@ -39,6 +39,7 @@ define Package/libtasn1/description
  Distinguish Encoding Rules (DER) manipulation.
 endef
 
+HOST_CFLAGS += -std=gnu99
 TARGET_CFLAGS += -ffunction-sections -fdata-sections
 TARGET_LDFLAGS += -Wl,--gc-sections