diff --git a/Makefile.frag.w32 b/Makefile.frag.w32
index bab7d26..190851d 100644
--- a/Makefile.frag.w32
+++ b/Makefile.frag.w32
@@ -1,6 +1,8 @@
 
 CMAKE=cmake.exe
 PHP_BINARY=$(PHP_PREFIX)\php.exe
+set path = where.exe composer.phar
+COMPOSER_PHAR = %%path%%
 
 CMAKE_CONFIGURE = $(CMAKE) -DCMAKE_INSTALL_PREFIX=$(AWSCRT_DIR)\build\install -DCMAKE_PREFIX_PATH=$(AWSCRT_DIR)\build\install -DBUILD_TESTING=OFF -DCMAKE_BUILD_TYPE=$(CMAKE_BUILD_TYPE)
 CMAKE_BUILD = $(CMAKE) --build
@@ -30,6 +32,5 @@ $(AWSCRT_DIR)\ext\api.h : $(AWSCRT_DIR)\src\api.h
 
 # Use PHPUnit and composer to run tests
 test-awscrt: install $(AWSCRT_DIR)\src\api.h $(BUILD_DIR)\php_awscrt.dll
-	COMPOSER_PHAR = where.exe composer.phar
 	$(PHP_BINARY) -c $(AWSCRT_DIR)\php-win.ini ${COMPOSER_PHAR} --working-dir=$(AWSCRT_DIR) update
 	$(PHP_BINARY) -c $(AWSCRT_DIR)\php-win.ini ${COMPOSER_PHAR} --working-dir=$(AWSCRT_DIR) run test-win
\ No newline at end of file