diff --git a/compat/mingw.c b/compat/mingw.c
index a5bc7b71e8..8d75d6d3e7 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -3104,6 +3104,18 @@ static size_t append_system_bin_dirs(char *path, size_t size)
 #endif
 #endif
 
+static int is_system32_path(const char *path)
+{
+	WCHAR system32[MAX_PATH], wpath[MAX_PATH];
+
+	if (xutftowcs_path(wpath, path) < 0 ||
+	    !GetSystemDirectoryW(system32, ARRAY_SIZE(system32)) ||
+	    _wcsicmp(system32, wpath))
+		return 0;
+
+	return 1;
+}
+
 static void setup_windows_environment(void)
 {
 	char *tmp = getenv("TMPDIR");
@@ -3144,7 +3156,8 @@ static void setup_windows_environment(void)
 			strbuf_addstr(&buf, tmp);
 			if ((tmp = getenv("HOMEPATH"))) {
 				strbuf_addstr(&buf, tmp);
-				if (is_directory(buf.buf))
+				if (!is_system32_path(buf.buf) &&
+				    is_directory(buf.buf))
 					setenv("HOME", buf.buf, 1);
 				else
 					tmp = NULL; /* use $USERPROFILE */