diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index de3c4179b2..d91b69ec02 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -3216,6 +3216,8 @@ public function filterBySpecifiedTypes(SpecifiedTypes $specifiedTypes): self
 				if (array_key_exists($conditionalExprString, $conditions)) {
 					continue;
 				}
+
+				// Pass 1: exact matching via equals()
 				foreach ($conditionalExpressions as $conditionalExpression) {
 					foreach ($conditionalExpression->getConditionExpressionTypeHolders() as $holderExprString => $conditionalTypeHolder) {
 						if (!array_key_exists($holderExprString, $specifiedExpressions) || !$specifiedExpressions[$holderExprString]->equals($conditionalTypeHolder)) {
@@ -3226,6 +3228,33 @@ public function filterBySpecifiedTypes(SpecifiedTypes $specifiedTypes): self
 					$conditions[$conditionalExprString][] = $conditionalExpression;
 					$specifiedExpressions[$conditionalExprString] = $conditionalExpression->getTypeHolder();
 				}
+
+				// Pass 2: use isSuperTypeOf for condition matching
+				// This handles cases where the condition type is broader than the
+				// narrowed type — e.g. 'value1'|'value2' (condition) won't match
+				// 'value1' (narrowed) via equals(), but should match via
+				// isSuperTypeOf. Only attempted when pass 1 found no matches, to
+				// avoid conflicts with broader conditions that have lower certainty
+				// from scope merging.
+				if (!array_key_exists($conditionalExprString, $conditions)) {
+					foreach ($conditionalExpressions as $conditionalExpression) {
+						foreach ($conditionalExpression->getConditionExpressionTypeHolders() as $holderExprString => $conditionalTypeHolder) {
+							if (!array_key_exists($holderExprString, $specifiedExpressions)) {
+								continue 2;
+							}
+							$specifiedHolder = $specifiedExpressions[$holderExprString];
+							if (!$specifiedHolder->getCertainty()->equals($conditionalTypeHolder->getCertainty())) {
+								continue 2;
+							}
+							if (!$conditionalTypeHolder->getType()->isSuperTypeOf($specifiedHolder->getType())->yes()) {
+								continue 2;
+							}
+						}
+
+						$conditions[$conditionalExprString][] = $conditionalExpression;
+						$specifiedExpressions[$conditionalExprString] = $conditionalExpression->getTypeHolder();
+					}
+				}
 			}
 		}
 
diff --git a/src/Analyser/TypeSpecifier.php b/src/Analyser/TypeSpecifier.php
index 126f057953..3d4475d593 100644
--- a/src/Analyser/TypeSpecifier.php
+++ b/src/Analyser/TypeSpecifier.php
@@ -1939,9 +1939,15 @@ private function processBooleanSureConditionalTypes(Scope $scope, SpecifiedTypes
 				continue;
 			}
 
+			$scopeType = $scope->getType($expr);
+			$conditionType = TypeCombinator::remove($scopeType, $type);
+			if ($scopeType->equals($conditionType)) {
+				continue;
+			}
+
 			$conditionExpressionTypes[$exprString] = ExpressionTypeHolder::createYes(
 				$expr,
-				TypeCombinator::remove($scope->getType($expr), $type),
+				$conditionType,
 			);
 		}
 
diff --git a/tests/PHPStan/Analyser/nsrt/bug-10055.php b/tests/PHPStan/Analyser/nsrt/bug-10055.php
new file mode 100644
index 0000000000..2464880ffc
--- /dev/null
+++ b/tests/PHPStan/Analyser/nsrt/bug-10055.php
@@ -0,0 +1,32 @@
+<?php // lint >= 8.0
+
+declare(strict_types = 1);
+
+namespace Bug10055;
+
+use function PHPStan\Testing\assertType;
+
+/**
+ * @param 'value1'|'value2'|'value3' $param1
+ * @param ($param1 is 'value3' ? bool : int) $param2
+ */
+function test(string $param1, int|bool $param2): void
+{
+	match ($param1) {
+		'value1' => assertType('int', $param2),
+		'value2' => assertType('int', $param2),
+		'value3' => assertType('bool', $param2),
+	};
+}
+
+function testScopeMerging(mixed $foo): void
+{
+	$a = 0;
+	if (\is_string($foo) || \is_int($foo)) {
+		$a = 1;
+	}
+
+	if (\is_int($foo)) {
+		assertType('1', $a);
+	}
+}
diff --git a/tests/PHPStan/Analyser/nsrt/bug-5051.php b/tests/PHPStan/Analyser/nsrt/bug-5051.php
index 6c3e80dce1..94ffc4711c 100644
--- a/tests/PHPStan/Analyser/nsrt/bug-5051.php
+++ b/tests/PHPStan/Analyser/nsrt/bug-5051.php
@@ -60,27 +60,27 @@ public function testWithBooleans($data): void
 			assertType('bool', $update);
 		} else {
 			assertType('1|2', $data);
-			assertType('bool', $update);
+			assertType('false', $update);
 		}
 
 		if ($data === 1) {
-			assertType('bool', $update);
-			assertType('bool', $foo);
+			assertType('false', $update);
+			assertType('false', $foo);
 		} else {
 			assertType('bool', $update);
 			assertType('bool', $foo);
 		}
 
 		if ($data === 2) {
-			assertType('bool', $update);
-			assertType('bool', $foo);
+			assertType('false', $update);
+			assertType('false', $foo);
 		} else {
 			assertType('bool', $update);
 			assertType('bool', $foo);
 		}
 
 		if ($data === 3) {
-			assertType('bool', $update);
+			assertType('false', $update);
 			assertType('true', $foo);
 		} else {
 			assertType('bool', $update);
@@ -88,7 +88,7 @@ public function testWithBooleans($data): void
 		}
 
 		if ($data === 1 || $data === 2) {
-			assertType('bool', $update);
+			assertType('false', $update);
 			assertType('false', $foo);
 		} else {
 			assertType('bool', $update);