--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,7 +13,8 @@ set(PROJECT_VERSION_PATCH "0-alpha5")
 set(PROJECT_VERSION
     ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}.${PROJECT_VERSION_PATCH})
 
-set(CMAKE_C_FLAGS "-Wall")
+# don't overwrite Debian CFLAGS
+#set(CMAKE_C_FLAGS "-Wall")
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
 # Handle cmake -D command line options
