diff --git a/include/boost/config/detail/suffix.hpp b/include/boost/config/detail/suffix.hpp
index b8b37d0b4..2423c35d6 100644
--- a/include/boost/config/detail/suffix.hpp
+++ b/include/boost/config/detail/suffix.hpp
@@ -1202,7 +1202,7 @@ namespace std{ using ::type_info; }
 #endif
 #endif
 
-#ifdef __has_include
+#if defined(__cplusplus) && defined(__has_include)
 #if !__has_include(<version>)
 #  define BOOST_NO_CXX20_HDR_VERSION
 #else
diff --git a/include/boost/config/stdlib/libcpp.hpp b/include/boost/config/stdlib/libcpp.hpp
index fc1d5bb4a..bc8536ead 100644
--- a/include/boost/config/stdlib/libcpp.hpp
+++ b/include/boost/config/stdlib/libcpp.hpp
@@ -104,7 +104,7 @@
 #  define BOOST_NO_CXX98_BINDERS
 #endif
 
-#ifdef __has_include
+#if defined(__cplusplus) && defined(__has_include)
 #if __has_include(<version>)
 #include <version>