diff --git a/locale/string_test.ha b/locale/string_test.ha
new file mode 100644
index 0000000..746aab3
--- /dev/null
+++ b/locale/string_test.ha
@@ -0,0 +1,18 @@
+@test fn string_resolve() void = {
+	assert(string_resolve([
+		(c, "c"),
+		(parse("xx_XX")!, "xx_XX"),
+	], c) as str == "c");
+	assert(string_resolve([
+		(c, "c"),
+		(parse("xx_XX")!, "xx_XX"),
+	], parse("xx_XX.UTF-8")!) as str == "xx_XX");
+	assert(string_resolve([
+		(c, "c"),
+		(parse("xx_XX")!, "xx_XX"),
+	], parse("yy_YY.UTF-8")!) as str == "c");
+	assert(string_resolve([
+		(parse("xx_XX")!, "xx_XX"),
+		(parse("zz_ZZ")!, "zz_ZZ"),
+	], parse("yy_YY")!) is void);
+};