diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2aea0393..880cd7a4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,9 +2,11 @@ cmake_minimum_required(VERSION 3.12)
 
 set(IRRLICHTMT_REVISION 15)
 
+# workaround: cmake<3.9 requires C language for internal checks
+# https://gitlab.kitware.com/cmake/cmake/-/merge_requests/487
 project(Irrlicht
 	VERSION 1.9.0.${IRRLICHTMT_REVISION}
-	LANGUAGES CXX
+        LANGUAGES C CXX
 )
 
 message(STATUS "*** Building IrrlichtMt ${PROJECT_VERSION} ***")