thodg/libgit2

diff --git a/tests/remote/httpproxy.c b/tests/remote/httpproxy.c
index 182ea24..8cd4371 100644
--- a/tests/remote/httpproxy.c
+++ b/tests/remote/httpproxy.c
@@ -152,6 +152,11 @@ void test_remote_httpproxy__env(void)
 	orig_no_proxy = cl_getenv("NO_PROXY");
 	orig_proxies_need_reset = 1;
 
+	/* Clear everything for a fresh start */
+	cl_setenv("HTTP_PROXY", NULL);
+	cl_setenv("HTTPS_PROXY", NULL);
+	cl_setenv("NO_PROXY", NULL);
+
 	/* HTTP proxy is ignored for HTTPS */
 	cl_setenv("HTTP_PROXY", "http://localhost:9/");
 	assert_proxy_is(NULL);
@@ -173,7 +178,11 @@ void test_remote_httpproxy__env(void)
 	cl_setenv("NO_PROXY", "github.dev,github.com,github.foo");
 	assert_proxy_is(NULL);
 
+	cl_setenv("HTTPS_PROXY", "");
+	assert_proxy_is(NULL);
+
 	/* configuration overrides environment variables */
+	cl_setenv("HTTPS_PROXY", "http://localhost:10/");
 	cl_setenv("NO_PROXY", "github.none");
 	assert_config_match("http.https://github.com.proxy", "http://localhost:11/");
 }