diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0213798..913cc8d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -33,7 +33,7 @@ set(MAKEFILE_EXTRACTED_VERSION "${KFVER_MAJOR}.${KFVER_MINOR}.${KFVER_PATCH}")
 #
 
 cmake_minimum_required(VERSION 3.6)
-project(kissfft VERSION "${MAKEFILE_EXTRACTED_VERSION}")
+project(kissfft VERSION "${MAKEFILE_EXTRACTED_VERSION}" LANGUAGES C)
 
 #
 # CMake configuration options
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 0a0e403..63389db 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -8,6 +8,8 @@ endfunction()
 
 set(KISSFFT_TEST_NUMFFTS 10000)
 
+enable_language(CXX)
+
 #
 # Add tools-independent fastfilt_* (../tools/fft_*) executable without adding a test
 #