diff --git a/library/pkcs5.c b/library/pkcs5.c
index 2717aaa..a517778 100644
--- a/library/pkcs5.c
+++ b/library/pkcs5.c
@@ -226,7 +226,7 @@
     unsigned int i;
     unsigned char md1[MBEDTLS_MD_MAX_SIZE];
     unsigned char work[MBEDTLS_MD_MAX_SIZE];
-    unsigned char md_size = mbedtls_md_get_size( ctx->md_info );
+    unsigned char md_size = mbedtls_md_get_size( mbedtls_md_get_handle( ctx ) );
     size_t use_len;
     unsigned char *out_p = output;
     unsigned char counter[4];