diff --git a/lib/nodes/Func.js b/lib/nodes/Func.js
index 53665bf..2cf5711 100644
--- a/lib/nodes/Func.js
+++ b/lib/nodes/Func.js
@@ -87,10 +87,9 @@ const allFunctions = [
 const vendorPrefixes = ['-webkit-', '-moz-', '-ms-', '-o-'];
 const reFunctions = new RegExp(`^(${vendorPrefixes.join('|')})?(${allFunctions.join('|')})`, 'i');
 const rePunctuation = new RegExp(`^(\\${Punctuation.chars.join('|\\')})`);
-
-const colorFunctionsRegex = /^(hsla?|hwb|lab|lch|rgba?)$/i;
-const varFunctionRegex = /^var$/i;
-const varPrefixRegex = /^--[^\s]+$/;
+const reColorFunctions = /^(hsla?|hwb|lab|lch|rgba?)$/i;
+const reVar = /^var$/i;
+const reVarPrefix = /^--[^\s]+$/;
 
 class Func extends Container {
   constructor(options = {}) {
@@ -192,9 +191,8 @@ class Func extends Container {
 
     const { lastNode } = parser;
     const { nodes } = node;
-    lastNode.isColor = colorFunctionsRegex.test(lastNode.name);
-    lastNode.isVar =
-      varFunctionRegex.test(lastNode.name) && nodes.length && varPrefixRegex.test(nodes[0].value);
+    lastNode.isColor = reColorFunctions.test(lastNode.name);
+    lastNode.isVar = reVar.test(lastNode.name) && nodes.length && reVarPrefix.test(nodes[0].value);
   }
 }