diff --git a/src/lsp/providers/diagnosticsProvider.ts b/src/lsp/providers/diagnosticsProvider.ts
index 9f483ac9f69be7fbc5deeae70607194fafacf66b..e76bf49249f86a753313ebc8aecd65c29403d89a 100644
--- a/src/lsp/providers/diagnosticsProvider.ts
+++ b/src/lsp/providers/diagnosticsProvider.ts
@@ -5,16 +5,10 @@   DiagnosticSeverity,
 } from 'vscode-languageserver'
 import { State } from '../util/state'
 import { isCssDoc } from '../util/css'
-import {
-  findClassNamesInRange,
-  findClassListsInDocument,
-  getClassNamesInClassList,
-} from '../util/find'
+import { findClassNamesInRange } from '../util/find'
 import { getClassNameMeta } from '../util/getClassNameMeta'
-import { getClassNameDecls } from '../util/getClassNameDecls'
-import { equal } from '../../util/array'
 
-function getCssDiagnostics(state: State, document: TextDocument): Diagnostic[] {
+function provideCssDiagnostics(state: State, document: TextDocument): void {
   const classNames = findClassNamesInRange(document, undefined, 'css')
 
   let diagnostics: Diagnostic[] = classNames
@@ -52,73 +46,38 @@       return {
         severity: DiagnosticSeverity.Error,
         range,
         message,
+        // source: 'ex',
       }
     })
     .filter(Boolean)
 
-  return diagnostics
-}
-
-function getConflictDiagnostics(
-  state: State,
-  document: TextDocument
-): Diagnostic[] {
-  let diagnostics: Diagnostic[] = []
-  const classLists = findClassListsInDocument(state, document)
-
-  classLists.forEach((classList) => {
-    const classNames = getClassNamesInClassList(classList)
+  // if (state.editor.capabilities.diagnosticRelatedInformation) {
+  //   diagnostic.relatedInformation = [
+  //     {
+  //       location: {
+  //         uri: document.uri,
+  //         range: Object.assign({}, diagnostic.range),
+  //       },
+  //       message: '',
+  //     },
+  //     {
+  //       location: {
+  //         uri: document.uri,
+  //         range: Object.assign({}, diagnostic.range),
+  //       },
+  //       message: '',
+  //     },
+  //   ]
+  // }
 
-    classNames.forEach((className, index) => {
-      let otherClassNames = classNames.filter((_className, i) => i !== index)
-      otherClassNames.forEach((otherClassName) => {
-        let decls = getClassNameDecls(state, className.className)
-        if (!decls) return
-
-        let otherDecls = getClassNameDecls(state, otherClassName.className)
-        if (!otherDecls) return
-
-        let meta = getClassNameMeta(state, className.className)
-        let otherMeta = getClassNameMeta(state, otherClassName.className)
-
-        if (
-          equal(Object.keys(decls), Object.keys(otherDecls)) &&
-          !Array.isArray(meta) &&
-          !Array.isArray(otherMeta) &&
-          equal(meta.context, otherMeta.context) &&
-          equal(meta.pseudo, otherMeta.pseudo)
-        ) {
-          diagnostics.push({
-            range: className.range,
-            severity: DiagnosticSeverity.Warning,
-            message: `You can’t use \`${className.className}\` and \`${otherClassName.className}\` together`,
-            relatedInformation: [
-              {
-                message: otherClassName.className,
-                location: {
-                  uri: document.uri,
-                  range: otherClassName.range,
-                },
-              },
-            ],
-          })
-        }
-      })
-    })
-  })
-
-  return diagnostics
+  state.editor.connection.sendDiagnostics({ uri: document.uri, diagnostics })
 }
 
 export async function provideDiagnostics(
   state: State,
   document: TextDocument
 ): Promise<void> {
-  state.editor.connection.sendDiagnostics({
-    uri: document.uri,
-    diagnostics: [
-      ...getConflictDiagnostics(state, document),
-      ...(isCssDoc(state, document) ? getCssDiagnostics(state, document) : []),
-    ],
-  })
+  if (isCssDoc(state, document)) {
+    return provideCssDiagnostics(state, document)
+  }
 }
diff --git a/src/lsp/util/find.ts b/src/lsp/util/find.ts
index 9a04ac4de58771e60379719acd0b50a5e1ebcdf2..6b1bfca7fbce3737b86c7529b4e7141715d17f58 100644
--- a/src/lsp/util/find.ts
+++ b/src/lsp/util/find.ts
@@ -6,7 +6,6 @@ import { isHtmlContext, isHtmlDoc, isSvelteDoc, isVueDoc } from './html'
 import { isWithinRange } from './isWithinRange'
 import { isJsContext, isJsDoc } from './js'
 import { getClassAttributeLexer } from './lexers'
-import { flatten } from '../../util/array'
 
 export function findAll(re: RegExp, str: string): RegExpMatchArray[] {
   let match: RegExpMatchArray
@@ -25,53 +24,44 @@   }
   return matches[matches.length - 1]
 }
 
-export function getClassNamesInClassList({
-  classList,
-  range,
-}: DocumentClassList): DocumentClassName[] {
-  const parts = classList.split(/(\s+)/)
-  const names: DocumentClassName[] = []
-  let index = 0
-  for (let i = 0; i < parts.length; i++) {
-    if (i % 2 === 0) {
-      const start = indexToPosition(classList, index)
-      const end = indexToPosition(classList, index + parts[i].length)
-      names.push({
-        className: parts[i],
-        range: {
-          start: {
-            line: range.start.line + start.line,
-            character:
-              (end.line === 0 ? range.start.character : 0) + start.character,
-          },
-          end: {
-            line: range.start.line + end.line,
-            character:
-              (end.line === 0 ? range.start.character : 0) + end.character,
-          },
-        },
-      })
-    }
-    index += parts[i].length
-  }
-  return names
-}
-
 export function findClassNamesInRange(
   doc: TextDocument,
   range?: Range,
   mode?: 'html' | 'css'
 ): DocumentClassName[] {
   const classLists = findClassListsInRange(doc, range, mode)
-  return flatten(classLists.map(getClassNamesInClassList))
-}
-
-export function findClassNamesInDocument(
-  state: State,
-  doc: TextDocument
-): DocumentClassName[] {
-  const classLists = findClassListsInDocument(state, doc)
-  return flatten(classLists.map(getClassNamesInClassList))
+  return [].concat.apply(
+    [],
+    classLists.map(({ classList, range }) => {
+      const parts = classList.split(/(\s+)/)
+      const names: DocumentClassName[] = []
+      let index = 0
+      for (let i = 0; i < parts.length; i++) {
+        if (i % 2 === 0) {
+          const start = indexToPosition(classList, index)
+          const end = indexToPosition(classList, index + parts[i].length)
+          names.push({
+            className: parts[i],
+            range: {
+              start: {
+                line: range.start.line + start.line,
+                character:
+                  (end.line === 0 ? range.start.character : 0) +
+                  start.character,
+              },
+              end: {
+                line: range.start.line + end.line,
+                character:
+                  (end.line === 0 ? range.start.character : 0) + end.character,
+              },
+            },
+          })
+        }
+        index += parts[i].length
+      }
+      return names
+    })
+  )
 }
 
 export function findClassListsInCssRange(
@@ -108,7 +98,7 @@ }
 
 export function findClassListsInHtmlRange(
   doc: TextDocument,
-  range?: Range
+  range: Range
 ): DocumentClassList[] {
   const text = doc.getText(range)
   const matches = findAll(/[\s:]class(?:Name)?=['"`{]/g, text)
@@ -184,16 +174,15 @@           return {
             classList: value,
             range: {
               start: {
-                line: (range?.start.line || 0) + start.line,
+                line: range.start.line + start.line,
                 character:
-                  (end.line === 0 ? range?.start.character || 0 : 0) +
+                  (end.line === 0 ? range.start.character : 0) +
                   start.character,
               },
               end: {
-                line: (range?.start.line || 0) + end.line,
+                line: range.start.line + end.line,
                 character:
-                  (end.line === 0 ? range?.start.character || 0 : 0) +
-                  end.character,
+                  (end.line === 0 ? range.start.character : 0) + end.character,
               },
             },
           }
@@ -207,8 +196,8 @@ }
 
 export function findClassListsInRange(
   doc: TextDocument,
-  range?: Range,
-  mode?: 'html' | 'css'
+  range: Range,
+  mode: 'html' | 'css'
 ): DocumentClassList[] {
   if (mode === 'css') {
     return findClassListsInCssRange(doc, range)