diff --git a/include/mbedtls/threading.h b/include/mbedtls/threading.h
index 66f78f5..2ec41a4 100644
--- a/include/mbedtls/threading.h
+++ b/include/mbedtls/threading.h
@@ -116,7 +116,7 @@
 /*
  * The preprocessor conditions above are the same as in platform_utils.c and
  * threading.c. Remember to update the code there when changing the conditions
- * here
+ * here.
  */
 extern mbedtls_threading_mutex_t mbedtls_threading_gmtime_mutex;
 #endif /* !_POSIX_VERSION || 200112L > _POSIX_THREAD_SAFE_FUNCTIONS */