diff --git a/lib/rules/function-calc-no-unspaced-operator/__tests__/index.js b/lib/rules/function-calc-no-unspaced-operator/__tests__/index.js
index f4bc6f9ebf..412710f879 100644
--- a/lib/rules/function-calc-no-unspaced-operator/__tests__/index.js
+++ b/lib/rules/function-calc-no-unspaced-operator/__tests__/index.js
@@ -115,6 +115,18 @@ testRule({
 			code: 'a { top: calc(-@x - 2rem); }',
 			description: 'Less variable syntax',
 		},
+		{
+			code: 'a { top: calc(@x-y * 2); }',
+			description: 'Less variable syntax with hyphens',
+		},
+		{
+			code: 'a { top: calc(-@x-y * 2); }',
+			description: 'Less variable syntax with hyphens and a unary operator',
+		},
+		{
+			code: 'a { top: calc(100% * @x-y); }',
+			description: 'Less variable syntax with hyphens at the end',
+		},
 		{
 			code: 'a { top: calc($x-y-z - 2rem); }',
 			description: 'postcss-simple-vars and SCSS variable with hyphens',
@@ -127,6 +139,18 @@ testRule({
 			code: 'a { top: calc(100% - #{$foo}); }',
 			description: 'Scss interpolation',
 		},
+		{
+			code: 'a { top: calc(#{$foo-bar} * 5); }',
+			description: 'Scss interpolation with hyphens',
+		},
+		{
+			code: 'a { top: calc(-#{$foo-bar} * 5); }',
+			description: 'Scss interpolation with hyphens and a unary operator',
+		},
+		{
+			code: 'a { top: calc(100% * #{$foo-bar}); }',
+			description: 'Scss interpolation with hyphens at the end',
+		},
 		{
 			code: 'a { top: calc(100% - #{map-get($container-max-widths, xl)}); }',
 			description: 'Scss interpolation with function',
diff --git a/lib/rules/function-calc-no-unspaced-operator/index.js b/lib/rules/function-calc-no-unspaced-operator/index.js
index 0c4846bcc3..c15e450232 100644
--- a/lib/rules/function-calc-no-unspaced-operator/index.js
+++ b/lib/rules/function-calc-no-unspaced-operator/index.js
@@ -4,6 +4,7 @@ const valueParser = require('postcss-value-parser');
 
 const declarationValueIndex = require('../../utils/declarationValueIndex');
 const getDeclarationValue = require('../../utils/getDeclarationValue');
+const isStandardSyntaxValue = require('../../utils/isStandardSyntaxValue');
 const report = require('../../utils/report');
 const ruleMessages = require('../../utils/ruleMessages');
 const setDeclarationValue = require('../../utils/setDeclarationValue');
@@ -166,6 +167,8 @@ const rule = (primary, _secondaryOptions, context) => {
 
 				if (firstNode.type !== 'word') return false;
 
+				if (!isStandardSyntaxValue(firstNode.value)) return false;
+
 				const operatorIndex = firstNode.value.search(OPERATOR_REGEX);
 				const operator = firstNode.value.slice(operatorIndex, operatorIndex + 1);