diff --git a/crypto/asn1/tasn_enc.c b/crypto/asn1/tasn_enc.c
index 9917d2a..0af9e9d 100644
--- a/crypto/asn1/tasn_enc.c
+++ b/crypto/asn1/tasn_enc.c
@@ -56,6 +56,7 @@
 
 #include <openssl/asn1.h>
 
+#include <assert.h>
 #include <limits.h>
 #include <string.h>