@@ -85,6 +85,8 @@ class UnionType implements CompoundType
 
 	private ?TrinaryLogic $isNull = null;
 
+	private ?TrinaryLogic $isCallable = null;
+
 	/**
 	 * @api
 	 * @param list<Type> $types
@@ -1126,7 +1128,7 @@ public function getEnumCaseObject(): ?EnumCaseObjectType
 
 	public function isCallable(): TrinaryLogic
 	{
-		return $this->unionResults(static fn (Type $type): TrinaryLogic => $type->isCallable());
+		return $this->isCallable ??= $this->unionResults(static fn (Type $type): TrinaryLogic => $type->isCallable());
 	}
 
 	public function getCallableParametersAcceptors(ClassMemberAccessAnswerer $scope): array
Original file line number	Diff line number	Diff line change
`@@ -85,6 +85,8 @@ class UnionType implements CompoundType`
`85`	`85`
`86`	`86`	`private ?TrinaryLogic $isNull = null;`
`87`	`87`
	`88`	`+ private ?TrinaryLogic $isCallable = null;`
	`89`	`+`
`88`	`90`	`/**`
`89`	`91`	`* @api`
`90`	`92`	`* @param list<Type> $types`
`@@ -1126,7 +1128,7 @@ public function getEnumCaseObject(): ?EnumCaseObjectType`
`1126`	`1128`
`1127`	`1129`	`public function isCallable(): TrinaryLogic`
`1128`	`1130`	`{`
`1129`		`- return $this->unionResults(static fn (Type $type): TrinaryLogic => $type->isCallable());`
	`1131`	`+ return $this->isCallable ??= $this->unionResults(static fn (Type $type): TrinaryLogic => $type->isCallable());`
`1130`	`1132`	`}`
`1131`	`1133`
`1132`	`1134`	`public function getCallableParametersAcceptors(ClassMemberAccessAnswerer $scope): array`