diff --git a/test/test-spawn.c b/test/test-spawn.c
index 3fd1f266..f383d652 100644
--- a/test/test-spawn.c
+++ b/test/test-spawn.c
@@ -388,7 +388,13 @@ TEST_IMPL(spawn_preserve_env) {
   options.stdio[1].data.stream = (uv_stream_t*) &out;
   options.stdio_count = 2;
 
-  ASSERT(setenv("ENV_TEST", "testval", 1) == 0);
+#ifdef _WIN32
+  r = putenv("ENV_TEST=testval");
+#else
+  r = setenv("ENV_TEST", "testval", 1);
+#endif
+  ASSERT(r == 0);
+
   /* Explicitly set options.env to NULL to test for env clobbering. */
   options.env = NULL;