diff --git a/Modules/Compiler/Clang-C.cmake b/Modules/Compiler/Clang-C.cmake
index 220e009bb02b2f956c519d8656ae148f3851a693..dc472d4647078ac4d4767b9d1f0ebc87a42d1b8d 100644
--- a/Modules/Compiler/Clang-C.cmake
+++ b/Modules/Compiler/Clang-C.cmake
@@ -60,7 +60,7 @@ if(CMAKE_C_COMPILER_VERSION VERSION_GREATER_EQUAL 3.0)
 endif()
 
 if(NOT "x${CMAKE_C_SIMULATE_ID}" STREQUAL "xMSVC")
-  __compiler_check_default_language_standard(C 3.4 99 3.6 11)
+  __compiler_check_default_language_standard(C 2.1 99 3.5.2 11)
 else()
   set(CMAKE_C_STANDARD_DEFAULT "")
 endif()