diff --git a/format/desktop_entry/error.ha b/format/desktop_entry/error.ha
index 0e46951..f59784d 100644
--- a/format/desktop_entry/error.ha
+++ b/format/desktop_entry/error.ha
@@ -1,4 +1,4 @@
-// Any error which may be returned from a function in this module.
+// All errors defined in this module.
 export type error = !(
 	invalid_group_header |
 	invalid_entry |
diff --git a/format/desktop_entry/parse.ha b/format/desktop_entry/parse.ha
index 2c11852..2439335 100644
--- a/format/desktop_entry/parse.ha
+++ b/format/desktop_entry/parse.ha
@@ -109,7 +109,7 @@ fn parse_entry(line: str) ((str, str, (locale::locale | void)) | error) = {
 		
 		local = match(locale::parse(local_string)) {
 		case let local: locale::locale => yield local;
-		case errors::invalid           => return invalid_entry;
+		case locale::invalid           => return invalid_entry;
 		};
 	};
 
diff --git a/locale/+linux.ha b/locale/+linux.ha
index 886492d..82efbba 100644
--- a/locale/+linux.ha
+++ b/locale/+linux.ha
@@ -52,29 +52,29 @@ fn get_locale(var: str) locale =
 		};
 	};
 
-fn get_locale_no_fallback(var: str) (locale | errors::invalid) =
+fn get_locale_no_fallback(var: str) (locale | invalid) =
 	match (get_env_locale(var)) {
 	case let local: locale => yield local;
 	case                   => yield (get_locale_conf_entry(var));
 	};
 
-fn get_env_locale(var: str) (locale | errors::invalid) =
+fn get_env_locale(var: str) (locale | invalid) =
 	match (os::getenv(var)) {
 	case let env: str => return parse(env);
-	case              => return errors::invalid;
+	case              => return invalid;
 	};
 
 let locale_conf: []str = [];
 
 @fini fn locale_conf() void = strings::freeall(locale_conf);
 
-fn get_locale_conf_entry(var: str) (locale | errors::invalid) = {
+fn get_locale_conf_entry(var: str) (locale | invalid) = {
 	get_locale_conf();
 	for (let entry .. locale_conf) {
 		let (key, value) = strings::cut(entry, "=");
 		if (key == var) return parse(value);
 	};
-	return errors::invalid;
+	return invalid;
 };
 
 fn get_locale_conf() []str = {
diff --git a/locale/-linux.ha b/locale/-linux.ha
index f31a887..b705b57 100644
--- a/locale/-linux.ha
+++ b/locale/-linux.ha
@@ -1,5 +1,3 @@
-use errors;
-
 // Returns the locale to use for character classification and case conversion.
 // The memory is statically allocated and must not be free'd. It may be
 // overwritten later, so use [[dup]] to extend its lifetime.
diff --git a/locale/error.ha b/locale/error.ha
new file mode 100644
index 0000000..7d357c0
--- /dev/null
+++ b/locale/error.ha
@@ -0,0 +1,7 @@
+// All errors defined in this module.
+export type error = !invalid;
+
+// Returned when a malformed locale is encountered.
+export type invalid = !void;
+
+export fn strerror(err: error) str = "invalid locale";
diff --git a/locale/locale.ha b/locale/locale.ha
index f514321..b72fcda 100644
--- a/locale/locale.ha
+++ b/locale/locale.ha
@@ -21,16 +21,16 @@ export def c = locale {
 //   lang_COUNTRY.ENCODING@MODIFIER
 // 
 // Where _COUNTRY, .ENCODING, and @MODIFIER may be omitted. The function
-// returns a [[locale]], or [[errors::invalid]] if the input cannot be parsed.
-// All memory is borrowed from the input, so [[finish]] should not be used to
-// free it.
-export fn parse(in: str) (locale | errors::invalid) = {
+// returns a [[locale]], or [[invalid]] if the input cannot be parsed. All
+// memory is borrowed from the input, so [[finish]] should not be used to free
+// it.
+export fn parse(in: str) (locale | invalid) = {
 	let (in, modifier) = strings::rcut(in, "@");
-	if (strings::compare(in, "") == 0) return void: errors::invalid;
+	if (strings::compare(in, "") == 0) return void: invalid;
 	let (in, encoding) = strings::rcut(in, ".");
-	if (strings::compare(in, "") == 0) return void: errors::invalid;
+	if (strings::compare(in, "") == 0) return void: invalid;
 	let (in, country) = strings::rcut(in, "_");
-	if (strings::compare(in, "") == 0) return void: errors::invalid;
+	if (strings::compare(in, "") == 0) return void: invalid;
 	return locale {
 		lang     = in,
 		country  = country,
diff --git a/locale/locale_test.ha b/locale/locale_test.ha
index d954d78..793c789 100644
--- a/locale/locale_test.ha
+++ b/locale/locale_test.ha
@@ -1,5 +1,4 @@
 use fmt;
-use errors;
 use strings;
 
 @test fn parse_full() void = {
@@ -64,8 +63,8 @@ use strings;
 
 @test fn parse_error() void = {
 	let local = match(parse("_COUNTRY.ENCODING@MODIFIER")) {
-	case errors::invalid => void;
-	case                 => abort("error");
+	case invalid => void;
+	case         => abort("no error");
 	};
 };