diff --git a/src/Type/BooleanType.php b/src/Type/BooleanType.php
index 0b0eb798ec..0e26b52a67 100644
--- a/src/Type/BooleanType.php
+++ b/src/Type/BooleanType.php
@@ -46,6 +46,16 @@ public function getConstantStrings(): array
 		return [];
 	}
 
+	public function getConstantScalarTypes(): array
+	{
+		return [new ConstantBooleanType(true), new ConstantBooleanType(false)];
+	}
+
+	public function getConstantScalarValues(): array
+	{
+		return [true, false];
+	}
+
 	public function describe(VerbosityLevel $level): string
 	{
 		return 'bool';
diff --git a/src/Type/Php/MbStrlenFunctionReturnTypeExtension.php b/src/Type/Php/MbStrlenFunctionReturnTypeExtension.php
index 73bdfa483f..84464f30bd 100644
--- a/src/Type/Php/MbStrlenFunctionReturnTypeExtension.php
+++ b/src/Type/Php/MbStrlenFunctionReturnTypeExtension.php
@@ -8,7 +8,6 @@
 use PHPStan\Reflection\FunctionReflection;
 use PHPStan\Reflection\ParametersAcceptorSelector;
 use PHPStan\ShouldNotHappenException;
-use PHPStan\Type\BooleanType;
 use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
@@ -93,16 +92,7 @@ public function getTypeFromFunctionCall(
 		}
 
 		$argType = $scope->getType($args[0]->value);
-
-		if ($argType->isSuperTypeOf(new BooleanType())->yes()) {
-			$constantScalars = TypeCombinator::remove($argType, new BooleanType())->getConstantScalarTypes();
-			if (count($constantScalars) > 0) {
-				$constantScalars[] = new ConstantBooleanType(true);
-				$constantScalars[] = new ConstantBooleanType(false);
-			}
-		} else {
-			$constantScalars = $argType->getConstantScalarTypes();
-		}
+		$constantScalars = $argType->getConstantScalarTypes();
 
 		$lengths = [];
 		foreach ($constantScalars as $constantScalar) {
diff --git a/src/Type/Php/StrlenFunctionReturnTypeExtension.php b/src/Type/Php/StrlenFunctionReturnTypeExtension.php
index e50dc20676..40b1c85587 100644
--- a/src/Type/Php/StrlenFunctionReturnTypeExtension.php
+++ b/src/Type/Php/StrlenFunctionReturnTypeExtension.php
@@ -5,8 +5,6 @@
 use PhpParser\Node\Expr\FuncCall;
 use PHPStan\Analyser\Scope;
 use PHPStan\Reflection\FunctionReflection;
-use PHPStan\Type\BooleanType;
-use PHPStan\Type\Constant\ConstantBooleanType;
 use PHPStan\Type\Constant\ConstantIntegerType;
 use PHPStan\Type\Constant\ConstantStringType;
 use PHPStan\Type\DynamicFunctionReturnTypeExtension;
@@ -44,16 +42,7 @@ public function getTypeFromFunctionCall(
 		}
 
 		$argType = $scope->getType($args[0]->value);
-
-		if ($argType->isSuperTypeOf(new BooleanType())->yes()) {
-			$constantScalars = TypeCombinator::remove($argType, new BooleanType())->getConstantScalarTypes();
-			if (count($constantScalars) > 0) {
-				$constantScalars[] = new ConstantBooleanType(true);
-				$constantScalars[] = new ConstantBooleanType(false);
-			}
-		} else {
-			$constantScalars = $argType->getConstantScalarTypes();
-		}
+		$constantScalars = $argType->getConstantScalarTypes();
 
 		$lengths = [];
 		foreach ($constantScalars as $constantScalar) {
diff --git a/tests/PHPStan/Analyser/nsrt/bug-10952b.php b/tests/PHPStan/Analyser/nsrt/bug-10952b.php
index f8f70e07d0..02386aa4b7 100644
--- a/tests/PHPStan/Analyser/nsrt/bug-10952b.php
+++ b/tests/PHPStan/Analyser/nsrt/bug-10952b.php
@@ -37,5 +37,14 @@ public function test(): void
 			mb_strlen($string) > 0 => assertType('non-empty-string', $string),
 			default => assertType("''", $string),
 		};
+
+		assertType('int<0, 1>', strlen($this->getBool()));
+		assertType('int<0, 1>', mb_strlen($this->getBool()));
 	}
+
+	public function getBool(): bool
+	{
+		return rand(0, 1) === 1;
+	}
+
 }
diff --git a/tests/PHPStan/Analyser/nsrt/bug-11201.php b/tests/PHPStan/Analyser/nsrt/bug-11201.php
index 202e5b1700..17890a823c 100644
--- a/tests/PHPStan/Analyser/nsrt/bug-11201.php
+++ b/tests/PHPStan/Analyser/nsrt/bug-11201.php
@@ -53,4 +53,4 @@ function returnsBool(): bool {
 assertType("'                   1'", $s);
 
 $s = sprintf('%20s', returnsBool());
-assertType("lowercase-string&non-falsy-string", $s);
+assertType("'                    '|'                   1'", $s);
diff --git a/tests/PHPStan/Analyser/nsrt/implode.php b/tests/PHPStan/Analyser/nsrt/implode.php
index 51e121a4c1..16f060465c 100644
--- a/tests/PHPStan/Analyser/nsrt/implode.php
+++ b/tests/PHPStan/Analyser/nsrt/implode.php
@@ -51,4 +51,9 @@ public function constArrays5($constArr) {
 	public function constArrays6($constArr) {
 		assertType("string", implode('', $constArr));
 	}
+
+	/** @param array{10: 1|2|bool, xy: 'a'|'b'|'c'} $constArr */
+	public function constArrays7($constArr) {
+		assertType("'1a'|'1b'|'1c'|'2a'|'2b'|'2c'|'a'|'b'|'c'", implode('', $constArr));
+	}
 }