diff --git a/index.js b/index.js
index e5bb9db..387c561 100644
--- a/index.js
+++ b/index.js
@@ -9,5 +9,5 @@ module.exports = string => {
 	// Use a simple backslash escape when it’s always valid, and a \unnnn escape when the simpler form would be disallowed by Unicode patterns’ stricter grammar.
 	return string
 		.replace(/[|\\{}()[\]^$+*?.]/g, '\\$&')
-		.replace(/-/g, '\\u002d');
+		.replace(/-/g, '\\x2d');
 };
diff --git a/package.json b/package.json
index 5f313f2..c6eb4a9 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "escape-string-regexp",
-	"version": "3.0.0",
+	"version": "4.0.0",
 	"description": "Escape RegExp special characters",
 	"license": "MIT",
 	"repository": "sindresorhus/escape-string-regexp",
diff --git a/test.js b/test.js
index fe5f549..e50f40b 100644
--- a/test.js
+++ b/test.js
@@ -8,10 +8,10 @@ test('main', t => {
 	);
 });
 
-test('escapes `-`', t => {
+test('escapes `-` in a way compatible with PCRE', t => {
 	t.is(
 		escapeStringRegexp('foo - bar'),
-		'foo \\u002d bar'
+		'foo \\x2d bar'
 	);
 });