diff --git a/node_modules/postcss-selector-parser/dist/parser.js b/node_modules/postcss-selector-parser/dist/parser.js
index b4c75e3edc3fe..144f91f730099 100644
--- a/node_modules/postcss-selector-parser/dist/parser.js
+++ b/node_modules/postcss-selector-parser/dist/parser.js
@@ -116,7 +116,8 @@ var Parser = /*#__PURE__*/function () {
           line: 1,
           column: 1
         }
-      }
+      },
+      sourceIndex: 0
     });
     this.root.append(selector);
     this.current = selector;
@@ -577,7 +578,8 @@ var Parser = /*#__PURE__*/function () {
     var selector = new _selector["default"]({
       source: {
         start: tokenStart(this.tokens[this.position + 1])
-      }
+      },
+      sourceIndex: this.tokens[this.position + 1][_tokenize.FIELDS.START_POS]
     });
     this.current.parent.append(selector);
     this.current = selector;
@@ -646,8 +648,9 @@ var Parser = /*#__PURE__*/function () {
     if (last && last.type === types.PSEUDO) {
       var selector = new _selector["default"]({
         source: {
-          start: tokenStart(this.tokens[this.position - 1])
-        }
+          start: tokenStart(this.tokens[this.position])
+        },
+        sourceIndex: this.tokens[this.position][_tokenize.FIELDS.START_POS]
       });
       var cache = this.current;
       last.append(selector);
diff --git a/node_modules/postcss-selector-parser/package.json b/node_modules/postcss-selector-parser/package.json
index 0d1af5d373f20..0a1bc95700dbb 100644
--- a/node_modules/postcss-selector-parser/package.json
+++ b/node_modules/postcss-selector-parser/package.json
@@ -1,6 +1,6 @@
 {
   "name": "postcss-selector-parser",
-  "version": "6.0.16",
+  "version": "6.1.0",
   "devDependencies": {
     "@babel/cli": "^7.11.6",
     "@babel/core": "^7.11.6",
diff --git a/package-lock.json b/package-lock.json
index c0ba79f6c6282..b5cc68d502f1b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9709,9 +9709,10 @@
       }
     },
     "node_modules/postcss-selector-parser": {
-      "version": "6.0.16",
-      "resolved": "https://registry.npmjs.org/postcss-selector-parser/-/postcss-selector-parser-6.0.16.tgz",
-      "integrity": "sha512-A0RVJrX+IUkVZbW3ClroRWurercFhieevHB38sr2+l9eUClMqome3LmEmnhlNy+5Mr2EYN6B2Kaw9wYdd+VHiw==",
+      "version": "6.1.0",
+      "resolved": "https://registry.npmjs.org/postcss-selector-parser/-/postcss-selector-parser-6.1.0.tgz",
+      "integrity": "sha512-UMz42UD0UY0EApS0ZL9o1XnLhSTtvvvLe5Dc2H2O56fvRZi+KulDyf5ctDhhtYJBGKStV2FL1fy6253cmLgqVQ==",
+      "license": "MIT",
       "dependencies": {
         "cssesc": "^3.0.0",
         "util-deprecate": "^1.0.2"