diff --git a/packages/wxt/src/core/utils/__tests__/validation.test.ts b/packages/wxt/src/core/utils/__tests__/validation.test.ts
index 9ca603fc..24f6fed7 100644
--- a/packages/wxt/src/core/utils/__tests__/validation.test.ts
+++ b/packages/wxt/src/core/utils/__tests__/validation.test.ts
@@ -72,9 +72,10 @@ describe('Validation Utils', () => {
       expect(actual).toEqual(expected);
     });
 
-    it("should return an error when content scripts don't have a matches", () => {
+    it('should return an error when "registration: manifest" content scripts don\'t have matches', () => {
       const entrypoint = fakeContentScriptEntrypoint({
         options: {
+          registration: 'manifest',
           // @ts-expect-error
           matches: null,
         },
@@ -83,7 +84,8 @@ describe('Validation Utils', () => {
         errors: [
           {
             type: 'error',
-            message: '`matches` is required',
+            message:
+              '`matches` is required for manifest registered content scripts',
             value: null,
             entrypoint,
           },
@@ -96,5 +98,24 @@ describe('Validation Utils', () => {
 
       expect(actual).toEqual(expected);
     });
+
+    it('should allow "registration: runtime" content scripts to not have matches', () => {
+      const entrypoint = fakeContentScriptEntrypoint({
+        options: {
+          registration: 'runtime',
+          // @ts-expect-error
+          matches: null,
+        },
+      });
+      const expected = {
+        errors: [],
+        errorCount: 0,
+        warningCount: 0,
+      };
+
+      const actual = validateEntrypoints([entrypoint]);
+
+      expect(actual).toEqual(expected);
+    });
   });
 });
diff --git a/packages/wxt/src/core/utils/validation.ts b/packages/wxt/src/core/utils/validation.ts
index d8189e85..331fe80a 100644
--- a/packages/wxt/src/core/utils/validation.ts
+++ b/packages/wxt/src/core/utils/validation.ts
@@ -30,10 +30,13 @@ function validateContentScriptEntrypoint(
   definition: ContentScriptEntrypoint,
 ): ValidationResult[] {
   const errors = validateBaseEntrypoint(definition);
-  if (definition.options.matches == null) {
+  if (
+    definition.options.registration !== 'runtime' &&
+    definition.options.matches == null
+  ) {
     errors.push({
       type: 'error',
-      message: '`matches` is required',
+      message: '`matches` is required for manifest registered content scripts',
       value: definition.options.matches,
       entrypoint: definition,
     });