diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index 6955246b0..96340e88b 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -786,7 +786,7 @@
 #define MBEDTLS_THREADING_IMPL
 #endif
 
-/* Ensurethat precisely one hash is enabled. */
+/* Ensure that precisely one hash is enabled. */
 #if defined(MBEDTLS_MD_SINGLE_HASH)
 
 #if defined(MBEDTLS_SHA256_C)