diff --git a/win32_functional_tests/Makefile b/win32_functional_tests/Makefile
index 89b611ccae..e246cfca6e 100644
--- a/win32_functional_tests/Makefile
+++ b/win32_functional_tests/Makefile
@@ -6,9 +6,9 @@
 # Compiler options here.
 ifeq ($(USE_OPT),)
 # this config if debugging is needed, but the binary is about 50M
-# USE_OPT = -c -Wall -O0 -ggdb -g3 -Werror-implicit-function-declaration -Werror -Wno-error=pointer-sign -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=sign-compare -Wno-error=unused-parameter -Wno-error=missing-field-initializers -Wno-error=write-strings
+# USE_OPT = -Wall -O0 -ggdb -g3 -Werror-implicit-function-declaration -Werror -Wno-error=pointer-sign -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=sign-compare -Wno-error=unused-parameter -Wno-error=missing-field-initializers -Wno-error=write-strings
 # this config producec a smaller binary file
-  USE_OPT = -c -Wall -O2           -Werror-implicit-function-declaration  -Wno-error=pointer-sign -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=sign-compare -Wno-error=unused-parameter -Wno-error=missing-field-initializers -Wno-error=write-strings -Wno-error=strict-aliasing
+  USE_OPT = -Wall -O2           -Werror-implicit-function-declaration  -Wno-error=pointer-sign -Wno-error=unused-function -Wno-error=unused-variable -Wno-error=sign-compare -Wno-error=unused-parameter -Wno-error=missing-field-initializers -Wno-error=write-strings -Wno-error=strict-aliasing
 
 	ifeq ($(OS),Windows_NT)
 	else