diff --git a/packages/eslint-plugin-antfu/src/rules/generic-spacing.test.ts b/packages/eslint-plugin-antfu/src/rules/generic-spacing.test.ts
index 9adb31c557..01b7735c7b 100644
--- a/packages/eslint-plugin-antfu/src/rules/generic-spacing.test.ts
+++ b/packages/eslint-plugin-antfu/src/rules/generic-spacing.test.ts
@@ -9,6 +9,7 @@ type Foo<
   T = true,
   K = false
 > = T`,
+  'type Foo<T extends true = true> = T',
 ]
 const invalids = [
   ['type Foo<T=true> = T', 'type Foo<T = true> = T'],
diff --git a/packages/eslint-plugin-antfu/src/rules/generic-spacing.ts b/packages/eslint-plugin-antfu/src/rules/generic-spacing.ts
index 98426ba50b..0345c3a06e 100644
--- a/packages/eslint-plugin-antfu/src/rules/generic-spacing.ts
+++ b/packages/eslint-plugin-antfu/src/rules/generic-spacing.ts
@@ -48,7 +48,8 @@ export default createEslintRule<Options, MessageIds>({
       TSTypeParameter: (node) => {
         if (!node.default)
           return
-        const from = node.name.range[1]
+        const endNode = node.constraint || node.name
+        const from = endNode.range[1]
         const to = node.default.range[0]
         if (sourceCode.text.slice(from, to) !== ' = ') {
           context.report({
@@ -56,7 +57,7 @@ export default createEslintRule<Options, MessageIds>({
               yield fixer.replaceTextRange([from, to], ' = ')
             },
             loc: {
-              start: node.name.loc.end,
+              start: endNode.loc.end,
               end: node.default.loc.start,
             },
             messageId: 'genericSpacingMismatch',