diff --git a/ChangeLog.d/missing-debug-message-arguments_mbedtls_ssl_decrypt_buf.txt b/ChangeLog.d/missing-debug-message-arguments_mbedtls_ssl_decrypt_buf.txt
new file mode 100644
index 0000000..e03178f
--- /dev/null
+++ b/ChangeLog.d/missing-debug-message-arguments_mbedtls_ssl_decrypt_buf.txt
@@ -0,0 +1,2 @@
+Bugfix
+  * Add missing arguments of debug message in mbedtls_ssl_decrypt_buf.
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index bdf882d..0718d5a 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -1384,7 +1384,9 @@
         /* Check that there's space for the authentication tag. */
         if( rec->data_len < transform->taglen )
         {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < taglen (%d) " ) );
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "msglen (%d) < taglen (%d) ",
+                                        rec->data_len,
+                                        transform->taglen ) );
             return( MBEDTLS_ERR_SSL_INVALID_MAC );
         }
         rec->data_len -= transform->taglen;