diff --git a/src/rules/no-important.js b/src/rules/no-important.js
index dc63aa04..b79af589 100644
--- a/src/rules/no-important.js
+++ b/src/rules/no-important.js
@@ -51,7 +51,7 @@ export default /** @satisfies {NoImportantRuleDefinition} */ ({
 
 		return {
 			Declaration(node) {
-				if (node.important) {
+				if (node.important === true) {
 					const declarationText = sourceCode.getText(node);
 					const textWithoutComments = declarationText.replace(
 						commentPattern,
diff --git a/tests/rules/no-important.test.js b/tests/rules/no-important.test.js
index be6ee62f..e14ba964 100644
--- a/tests/rules/no-important.test.js
+++ b/tests/rules/no-important.test.js
@@ -50,6 +50,9 @@ ruleTester.run("no-important", rule, {
 		"a { color: red /* !important */; }",
 		"a { color: /* !important */ red; }",
 		"a { color: red; /* !important */ background: blue; }",
+		"a { color: red !ie; }",
+		"a { color: red !IE7; }",
+		"a { color: red !important\\9; }",
 	],
 	invalid: [
 		{