diff --git a/src/syntax-definitions.ts b/src/syntax-definitions.ts
index fdf3896..ec9b3ea 100644
--- a/src/syntax-definitions.ts
+++ b/src/syntax-definitions.ts
@@ -402,8 +402,7 @@ const selectors4SyntaxDefinition = extendSyntaxDefinition(selectors3SyntaxDefini
     },
     pseudoElements: {
         definitions: {
-            NoArgument: ['marker'],
-            Selector: ['part']
+            NoArgument: ['marker']
         }
     }
 });
@@ -489,7 +488,7 @@ export const cssModules = {
         latest: true,
         pseudoElements: {
             definitions: {
-                Selector: ['part']
+                String: ['part']
             }
         }
     }
diff --git a/test/modules.test.ts b/test/modules.test.ts
index 671a17b..aac00a1 100644
--- a/test/modules.test.ts
+++ b/test/modules.test.ts
@@ -397,13 +397,7 @@ describe('CSS Modules', () => {
                             items: [
                                 ast.pseudoElement({
                                     name: 'part',
-                                    argument: ast.selector({
-                                        rules: [
-                                            ast.rule({
-                                                items: [ast.tagName({name: 'button'})]
-                                            })
-                                        ]
-                                    })
+                                    argument: ast.string({value: 'button'})
                                 })
                             ]
                         })
@@ -444,13 +438,7 @@ describe('CSS Modules', () => {
                             items: [
                                 ast.pseudoElement({
                                     name: 'part',
-                                    argument: ast.selector({
-                                        rules: [
-                                            ast.rule({
-                                                items: [ast.tagName({name: 'button'})]
-                                            })
-                                        ]
-                                    })
+                                    argument: ast.string({value: 'button'})
                                 })
                             ]
                         })
@@ -465,13 +453,7 @@ describe('CSS Modules', () => {
                             items: [
                                 ast.pseudoElement({
                                     name: 'part',
-                                    argument: ast.selector({
-                                        rules: [
-                                            ast.rule({
-                                                items: [ast.tagName({name: 'button-primary'})]
-                                            })
-                                        ]
-                                    })
+                                    argument: ast.string({value: 'button-primary'})
                                 })
                             ]
                         })
@@ -635,13 +617,7 @@ describe('CSS Modules', () => {
                             items: [
                                 ast.pseudoElement({
                                     name: 'part',
-                                    argument: ast.selector({
-                                        rules: [
-                                            ast.rule({
-                                                items: [ast.tagName({name: 'button'})]
-                                            })
-                                        ]
-                                    })
+                                    argument: ast.string({value: 'button'})
                                 })
                             ]
                         })
@@ -677,13 +653,7 @@ describe('CSS Modules', () => {
                             items: [
                                 ast.pseudoElement({
                                     name: 'part',
-                                    argument: ast.selector({
-                                        rules: [
-                                            ast.rule({
-                                                items: [ast.tagName({name: 'button'})]
-                                            })
-                                        ]
-                                    })
+                                    argument: ast.string({value: 'button'})
                                 })
                             ]
                         })