diff --git a/src/Property/Selector.php b/src/Property/Selector.php
index cf07a8f5..130a18ac 100644
--- a/src/Property/Selector.php
+++ b/src/Property/Selector.php
@@ -46,7 +46,7 @@ class Selector
         /ix';
 
     /**
-     * regexp for specificity calculations
+     * regexp for validity verifications
      *
      * @var string
      *
@@ -79,7 +79,9 @@ class Selector
      */
     public static function isValid($sSelector)
     {
-        return \preg_match(static::SELECTOR_VALIDATION_RX, $sSelector);
+        return \preg_match(static::SELECTOR_VALIDATION_RX, $sSelector)
+            // trim quoted texts and validate colons on the remainder
+            && !\preg_match('/(?<!\\\\):\s/', \preg_replace('/([\'"]).*?(?<!\\\\)\\1/', '', $sSelector));
     }
 
     /**
diff --git a/tests/ParserTest.php b/tests/ParserTest.php
index 2c1c7287..f8f32a39 100644
--- a/tests/ParserTest.php
+++ b/tests/ParserTest.php
@@ -787,6 +787,14 @@ public function invalidSelectorsInFile(): void
 	html[dir="rtl"] .super-menu > li:last-of-type {border-left-width: 0;}}
 body {background-color: red;}';
         self::assertSame($sExpected, $oDoc->render());
+
+        $oDoc = self::parsedStructureForFile('invalid-selectors-4', Settings::create()->withMultibyteSupport(true));
+        $sExpected = 'body, div :hover {color: green;}
+div {color: blue;}
+a[href*=": \" "] {color: blue;}
+a[href*=\': \" \'] {color: blue;}
+#some_id_that_ends_in_a\: > a {color: blue;}';
+        self::assertSame($sExpected, $oDoc->render());
     }
 
     /**
diff --git a/tests/fixtures/invalid-selectors-4.css b/tests/fixtures/invalid-selectors-4.css
new file mode 100644
index 00000000..787a301f
--- /dev/null
+++ b/tests/fixtures/invalid-selectors-4.css
@@ -0,0 +1,27 @@
+body, div: hover {
+    color: green;
+}
+
+body, div : hover {
+    color: green;
+}
+
+body, div :hover {
+    color: green;
+}
+
+div {
+    color: blue;
+}
+
+a[href*=": \" "] {
+    color: blue;
+}
+
+a[href*=': \" '] {
+    color: blue;
+}
+
+#some_id_that_ends_in_a\: > a {
+    color: blue;
+}