diff --git a/CompilerChecks.cmake b/CompilerChecks.cmake
index 81fb5462..9719e699 100644
--- a/CompilerChecks.cmake
+++ b/CompilerChecks.cmake
@@ -48,6 +48,7 @@ if (UNIX)
     add_c_compiler_flag("-Werror=implicit-int" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Wint-conversion" SUPPORTED_COMPILER_FLAGS)
     add_c_compiler_flag("-Werror=int-conversion" SUPPORTED_COMPILER_FLAGS)
+    add_c_compiler_flag("-Werror=unused-variable" SUPPORTED_COMPILER_FLAGS)
 
     check_c_compiler_flag("-Wformat" REQUIRED_FLAGS_WFORMAT)
     if (REQUIRED_FLAGS_WFORMAT)