diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index 26f30b5d1..65eab4b40 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -884,7 +884,7 @@ int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
         /*
          * Prefix record content with dynamic IV in case it is explicit.
          */
-        if( dynamic_iv_is_explicit )
+        if( dynamic_iv_is_explicit != 0 )
         {
             if( rec->data_offset < dynamic_iv_len )
             {