diff --git a/src/Type/Php/RegexGroupParser.php b/src/Type/Php/RegexGroupParser.php
index f63959e78d..83dbf58b7d 100644
--- a/src/Type/Php/RegexGroupParser.php
+++ b/src/Type/Php/RegexGroupParser.php
@@ -21,7 +21,6 @@
 use PHPStan\Type\TypeCombinator;
 use function array_key_exists;
 use function count;
-use function implode;
 use function in_array;
 use function is_int;
 use function rtrim;
@@ -284,10 +283,22 @@ private function createGroupType(TreeNode $group, bool $maybeConstant): Type
 		$inOptionalQuantification = false;
 		$onlyLiterals = [];
 
-		$this->walkGroupAst($group, $isNonEmpty, $isNumeric, $inOptionalQuantification, $onlyLiterals);
+		$this->walkGroupAst(
+			$group,
+			$isNonEmpty,
+			$isNumeric,
+			$inOptionalQuantification,
+			$onlyLiterals,
+			false,
+		);
 
 		if ($maybeConstant && $onlyLiterals !== null && $onlyLiterals !== []) {
-			return new ConstantStringType(implode('', $onlyLiterals));
+			$result = [];
+			foreach ($onlyLiterals as $literal) {
+				$result[] = new ConstantStringType($literal);
+
+			}
+			return TypeCombinator::union(...$result);
 		}
 
 		if ($isNumeric->yes()) {
@@ -306,7 +317,14 @@ private function createGroupType(TreeNode $group, bool $maybeConstant): Type
 	/**
 	 * @param array<string>|null $onlyLiterals
 	 */
-	private function walkGroupAst(TreeNode $ast, TrinaryLogic &$isNonEmpty, TrinaryLogic &$isNumeric, bool &$inOptionalQuantification, ?array &$onlyLiterals): void
+	private function walkGroupAst(
+		TreeNode $ast,
+		TrinaryLogic &$isNonEmpty,
+		TrinaryLogic &$isNumeric,
+		bool &$inOptionalQuantification,
+		?array &$onlyLiterals,
+		bool $inClass,
+	): void
 	{
 		$children = $ast->getChildren();
 
@@ -327,8 +345,24 @@ private function walkGroupAst(TreeNode $ast, TrinaryLogic &$isNonEmpty, TrinaryL
 			}
 
 			$onlyLiterals = null;
+		} elseif ($ast->getId() === '#class' && $onlyLiterals !== null) {
+			$inClass = true;
+
+			$newLiterals = [];
+			foreach ($children as $child) {
+				$oldLiterals = $onlyLiterals;
+
+				if ($child->getId() === 'token') {
+					$this->getLiteralValue($child, $oldLiterals, true);
+				}
+
+				foreach ($oldLiterals ?? [] as $oldLiteral) {
+					$newLiterals[] = $oldLiteral;
+				}
+			}
+			$onlyLiterals = $newLiterals;
 		} elseif ($ast->getId() === 'token') {
-			$literalValue = $this->getLiteralValue($ast, $onlyLiterals);
+			$literalValue = $this->getLiteralValue($ast, $onlyLiterals, !$inClass);
 			if ($literalValue !== null) {
 				if (Strings::match($literalValue, '/^\d+$/') === null) {
 					$isNumeric = TrinaryLogic::createNo();
@@ -360,6 +394,7 @@ private function walkGroupAst(TreeNode $ast, TrinaryLogic &$isNonEmpty, TrinaryL
 				$isNumeric,
 				$inOptionalQuantification,
 				$onlyLiterals,
+				$inClass,
 			);
 		}
 	}
@@ -367,7 +402,7 @@ private function walkGroupAst(TreeNode $ast, TrinaryLogic &$isNonEmpty, TrinaryL
 	/**
 	 * @param array<string>|null $onlyLiterals
 	 */
-	private function getLiteralValue(TreeNode $node, ?array &$onlyLiterals): ?string
+	private function getLiteralValue(TreeNode $node, ?array &$onlyLiterals, bool $appendLiterals): ?string
 	{
 		if ($node->getId() !== 'token') {
 			return null;
@@ -381,11 +416,18 @@ private function getLiteralValue(TreeNode $node, ?array &$onlyLiterals): ?string
 			if (strlen($value) > 1 && $value[0] === '\\') {
 				return substr($value, 1);
 			} elseif (
-				$token === 'literal'
+				$appendLiterals
+				&& $token === 'literal'
 				&& $onlyLiterals !== null
 				&& !in_array($value, ['.'], true)
 			) {
-				$onlyLiterals[] = $value;
+				if ($onlyLiterals === []) {
+					$onlyLiterals = [$value];
+				} else {
+					foreach ($onlyLiterals as &$literal) {
+						$literal .= $value;
+					}
+				}
 			}
 
 			return $value;
diff --git a/tests/PHPStan/Analyser/nsrt/bug-11311.php b/tests/PHPStan/Analyser/nsrt/bug-11311.php
index 0dfb7cc4b4..51cc0f094f 100644
--- a/tests/PHPStan/Analyser/nsrt/bug-11311.php
+++ b/tests/PHPStan/Analyser/nsrt/bug-11311.php
@@ -179,7 +179,7 @@ function (string $s): void {
 
 function (string $s): void {
 	if (preg_match('/^%([0-9]*\$)?[0-9]*\.?[0-9]*([sbdeEfFgGhHouxX])$/', $s, $matches, PREG_UNMATCHED_AS_NULL) === 1) {
-		assertType('array{string, non-empty-string|null, non-empty-string}', $matches);
+		assertType("array{string, non-empty-string|null, 'b'|'d'|'E'|'e'|'F'|'f'|'G'|'g'|'H'|'h'|'o'|'s'|'u'|'X'|'x'}", $matches);
 	}
 };
 
diff --git a/tests/PHPStan/Analyser/nsrt/preg_match_shapes.php b/tests/PHPStan/Analyser/nsrt/preg_match_shapes.php
index a940e62ff4..fde7690f7c 100644
--- a/tests/PHPStan/Analyser/nsrt/preg_match_shapes.php
+++ b/tests/PHPStan/Analyser/nsrt/preg_match_shapes.php
@@ -435,7 +435,7 @@ function (string $s, $mixed): void {
 
 function (string $s): void {
 	if (preg_match('/^%([0-9]*\$)?[0-9]*\.?[0-9]*([sbdeEfFgGhHouxX])$/', $s, $matches) === 1) {
-		assertType('array{string, string, non-empty-string}', $matches);
+		assertType("array{string, string, 'b'|'d'|'E'|'e'|'F'|'f'|'G'|'g'|'H'|'h'|'o'|'s'|'u'|'X'|'x'}", $matches);
 	}
 };
 
@@ -453,13 +453,13 @@ function (string $s): void {
 
 function (string $s): void {
 	if (preg_match('~^([157])$~', $s, $matches) === 1) {
-		assertType("array{string, numeric-string}", $matches);
+		assertType("array{string, '1'|'5'|'7'}", $matches);
 	}
 };
 
 function (string $s): void {
 	if (preg_match('~^([157XY])$~', $s, $matches) === 1) {
-		assertType("array{string, non-empty-string}", $matches);
+		assertType("array{string, '1'|'5'|'7'|'X'|'Y'}", $matches);
 	}
 };
 
@@ -519,10 +519,10 @@ function bug11323(string $s): void {
 		assertType('array{string, non-empty-string}', $matches);
 	}
 	if (preg_match("{([\r\n]+)(\n)([\n])}", $s, $matches)) {
-		assertType('array{string, non-empty-string, "\n", non-empty-string}', $matches);
+		assertType('array{string, non-empty-string, "\n", "\n"}', $matches);
 	}
 	if (preg_match('/foo(*:first)|bar(*:second)([x])/', $s, $matches)) {
-		assertType("array{0: string, 1?: non-empty-string, MARK?: 'first'|'second'}", $matches);
+		assertType("array{0: string, 1?: 'x', MARK?: 'first'|'second'}", $matches);
 	}
 }
 
@@ -570,3 +570,33 @@ function (string $s): void {
 		assertType("array{0: string, 1: non-empty-string, 2?: numeric-string, 3?: 'x'}", $matches);
 	}
 };
+
+function (string $s): void {
+	if (preg_match('/Price: ([a-z])/i', $s, $matches)) {
+		assertType("array{string, non-empty-string}", $matches);
+	}
+};
+
+function (string $s): void {
+	if (preg_match('/Price: ([0-9])/i', $s, $matches)) {
+		assertType("array{string, numeric-string}", $matches);
+	}
+};
+
+function (string $s): void {
+	if (preg_match('/Price: ([xXa])/i', $s, $matches)) {
+		assertType("array{string, 'a'|'X'|'x'}", $matches);
+	}
+};
+
+function (string $s): void {
+	if (preg_match('/Price: (ba[rz])/i', $s, $matches)) {
+		assertType("array{string, 'bar'|'baz'}", $matches);
+	}
+};
+
+function (string $s): void {
+	if (preg_match('/Price: (b[ao][mn])/i', $s, $matches)) {
+		assertType("array{string, 'bam'|'ban'|'bom'|'bon'}", $matches);
+	}
+};