diff --git a/lib/utils/__tests__/isStandardSyntaxRule.test.js b/lib/utils/__tests__/isStandardSyntaxRule.test.js
index 025ab14a04..199bb5d079 100644
--- a/lib/utils/__tests__/isStandardSyntaxRule.test.js
+++ b/lib/utils/__tests__/isStandardSyntaxRule.test.js
@@ -35,11 +35,11 @@ describe('isStandardSyntaxRule', () => {
 	it('custom-property-set', () => {
 		expect(isStandardSyntaxRule(node('--custom-property-set: {}'))).toBeFalsy();
 	});
-	it('Scss nested properties', () => {
+	it('scss nested properties', () => {
 		expect(isStandardSyntaxRule(node('foo: {};'))).toBeFalsy();
 	});
-	it('called Less class parametric mixin', () => {
-		expect(isStandardSyntaxRule(lessNode('.mixin-name(@var);'))).toBeFalsy();
+	it('less class parametric mixin', () => {
+		expect(isStandardSyntaxRule(lessNode('.mixin-name(@var) {}'))).toBeFalsy();
 	});
 	it('non-outputting parametric Less class mixin definition', () => {
 		expect(isStandardSyntaxRule(lessNode('.mixin-name() {}'))).toBeFalsy();
@@ -53,25 +53,13 @@ describe('isStandardSyntaxRule', () => {
 	it('non-outputting Less ID mixin definition', () => {
 		expect(isStandardSyntaxRule(lessNode('#mixin-name() {}'))).toBeFalsy();
 	});
-	it('called Less ID mixin', () => {
-		expect(isStandardSyntaxRule(lessNode('#mixin-name;'))).toBeFalsy();
-	});
-	it('called namespaced Less mixin (child)', () => {
-		expect(isStandardSyntaxRule(lessNode('#namespace > .mixin-name;'))).toBeFalsy();
-	});
-	it('called namespaced Less mixin (descendant)', () => {
-		expect(isStandardSyntaxRule(lessNode('#namespace .mixin-name;'))).toBeFalsy();
-	});
-	it('called namespaced Less mixin (compound)', () => {
-		expect(isStandardSyntaxRule(lessNode('#namespace.mixin-name;'))).toBeFalsy();
-	});
 	it('less mixin', () => {
 		expect(
 			isStandardSyntaxRule(lessNode('.box-shadow(@style, @c) when (iscolor(@c)) {}')),
 		).toBeFalsy();
 	});
 	it('less extend', () => {
-		expect(isStandardSyntaxRule(lessNode('&:extend(.inline);'))).toBeFalsy();
+		expect(isStandardSyntaxRule(lessNode('&:extend(.inline) {}'))).toBeFalsy();
 	});
 	it('less detached rulesets', () => {
 		expect(isStandardSyntaxRule(lessNode('@foo: {};'))).toBeFalsy();
@@ -79,6 +67,9 @@ describe('isStandardSyntaxRule', () => {
 	it('less guarded namespaces', () => {
 		expect(isStandardSyntaxRule(lessNode('#namespace when (@mode=huge) {}'))).toBeFalsy();
 	});
+	it('less parametric mixins', () => {
+		expect(isStandardSyntaxRule(lessNode('.mixin (@variable: 5) {}'))).toBeFalsy();
+	});
 	it('mixin guards', () => {
 		expect(
 			isStandardSyntaxRule(lessNode('.mixin (@variable) when (@variable = 10px) {}')),
diff --git a/lib/utils/__tests__/isStandardSyntaxSelector.test.js b/lib/utils/__tests__/isStandardSyntaxSelector.test.js
index d1cdc0050f..2f973e5845 100644
--- a/lib/utils/__tests__/isStandardSyntaxSelector.test.js
+++ b/lib/utils/__tests__/isStandardSyntaxSelector.test.js
@@ -42,6 +42,13 @@ describe('isStandardSyntaxSelector', () => {
 	it('SCSS interpolation (pseudo)', () => {
 		expect(isStandardSyntaxSelector(':n-#{$n}')).toBeFalsy();
 	});
+	it('SCSS placeholder', () => {
+		expect(isStandardSyntaxSelector('%foo')).toBeFalsy();
+	});
+	it('SCSS nested properties', () => {
+		expect(isStandardSyntaxSelector('.a { .b }')).toBeFalsy();
+		expect(isStandardSyntaxSelector('.a { &:hover }')).toBeFalsy();
+	});
 	it('Less interpolation', () => {
 		expect(isStandardSyntaxSelector('.n-@{n}')).toBeFalsy();
 	});
@@ -54,8 +61,8 @@ describe('isStandardSyntaxSelector', () => {
 	it('Less extend inside ruleset', () => {
 		expect(isStandardSyntaxSelector('a { &:extend(.a all) }')).toBeFalsy();
 	});
-	it('SCSS placeholder', () => {
-		expect(isStandardSyntaxSelector('%foo')).toBeFalsy();
+	it('Less mixin', () => {
+		expect(isStandardSyntaxSelector('.foo()')).toBeFalsy();
 	});
 	it('Less mixin with resolved nested selectors', () => {
 		expect(isStandardSyntaxSelector('.foo().bar')).toBeFalsy();
@@ -69,6 +76,10 @@ describe('isStandardSyntaxSelector', () => {
 		expect(isStandardSyntaxSelector('.foo()[bar]')).toBeFalsy();
 		expect(isStandardSyntaxSelector(".foo()[bar='baz']")).toBeFalsy();
 	});
+	it('Less parametric mixin', () => {
+		expect(isStandardSyntaxSelector('.foo(@a)')).toBeFalsy();
+		expect(isStandardSyntaxSelector('.foo(@a: 5px)')).toBeFalsy();
+	});
 
 	it('ERB templates', () => {
 		// E. g. like in https://github.com/stylelint/stylelint/issues/4489
diff --git a/lib/utils/isStandardSyntaxRule.js b/lib/utils/isStandardSyntaxRule.js
index 0772c19958..cc28563494 100644
--- a/lib/utils/isStandardSyntaxRule.js
+++ b/lib/utils/isStandardSyntaxRule.js
@@ -13,50 +13,12 @@ module.exports = function (rule) {
 		return false;
 	}
 
-	const raws = rule.raws;
-
-	// Get full selector
-	const selector = (raws.selector && raws.selector.raw) || rule.selector;
-
-	if (!isStandardSyntaxSelector(rule.selector)) {
-		return false;
-	}
-
-	// Called Less mixin (e.g. a { .mixin() })
-	// @ts-expect-error -- TODO TYPES support LESS and SASS types somehow
-	if (rule.mixin) {
-		return false;
-	}
-
-	// Less detached rulesets
-	if (selector.startsWith('@') && selector.endsWith(':')) {
-		return false;
-	}
-
 	// Ignore Less &:extend rule
 	if ('extend' in rule && rule.extend) {
 		return false;
 	}
 
-	// Ignore mixin or &:extend rule
-	// https://github.com/shellscape/postcss-less/blob/master/lib/less-parser.js#L52
-	// @ts-expect-error -- TODO TYPES support LESS and SASS types somehow
-	if (rule.params && rule.params[0]) {
-		return false;
-	}
-
-	// Non-outputting Less mixin definition (e.g. .mixin() {})
-	if (selector.endsWith(')') && !selector.includes(':')) {
-		return false;
-	}
-
-	// Less guards
-	if (/when\s+(not\s+)*\(/.test(selector)) {
-		return false;
-	}
-
-	// Ignore Scss nested properties
-	if (selector.endsWith(':')) {
+	if (!isStandardSyntaxSelector(rule.selector)) {
 		return false;
 	}
 
diff --git a/lib/utils/isStandardSyntaxSelector.js b/lib/utils/isStandardSyntaxSelector.js
index 7c446578b3..dd74d29e7d 100644
--- a/lib/utils/isStandardSyntaxSelector.js
+++ b/lib/utils/isStandardSyntaxSelector.js
@@ -19,6 +19,11 @@ module.exports = function (selector) {
 		return false;
 	}
 
+	// SCSS nested properties
+	if (selector.endsWith(':')) {
+		return false;
+	}
+
 	// Less :extend()
 	if (/:extend(\(.*?\))?/.test(selector)) {
 		return false;
@@ -29,6 +34,16 @@ module.exports = function (selector) {
 		return false;
 	}
 
+	// Less non-outputting mixin definition (e.g. .mixin() {})
+	if (selector.endsWith(')') && !selector.includes(':')) {
+		return false;
+	}
+
+	// Less Parametric mixins (e.g. .mixin(@variable: x) {})
+	if (/\(@.*\)$/.test(selector)) {
+		return false;
+	}
+
 	// ERB template tags
 	if (selector.includes('<%') || selector.includes('%>')) {
 		return false;