diff --git a/src/Type/ArrayType.php b/src/Type/ArrayType.php
index 986081b68ea..a8dce08d738 100644
--- a/src/Type/ArrayType.php
+++ b/src/Type/ArrayType.php
@@ -275,26 +275,30 @@ public function setOffsetValueType(?Type $offsetType, Type $valueType, bool $uni
 			$offsetType = self::castToArrayKeyType($offsetType);
 		}
 
-		if (
-			($offsetType instanceof ConstantStringType || $offsetType instanceof ConstantIntegerType)
-			&& $offsetType->isSuperTypeOf($this->keyType)->yes()
-		) {
-			$builder = ConstantArrayTypeBuilder::createEmpty();
-			$builder->setOffsetValueType($offsetType, $valueType);
-			return $builder->getArray();
-		}
-
-		$array = new self(
-			TypeCombinator::union($this->keyType, $offsetType),
-			$unionValues || $offsetType instanceof ConstantStringType || $offsetType instanceof ConstantIntegerType
-				? TypeCombinator::union($this->itemType, $valueType)
-				: $valueType,
-		);
 		if ($offsetType instanceof ConstantStringType || $offsetType instanceof ConstantIntegerType) {
-			return TypeCombinator::intersect($array, new HasOffsetValueType($offsetType, $valueType), new NonEmptyArrayType());
+			if ($offsetType->isSuperTypeOf($this->keyType)->yes()) {
+				$builder = ConstantArrayTypeBuilder::createEmpty();
+				$builder->setOffsetValueType($offsetType, $valueType);
+				return $builder->getArray();
+			}
+
+			return TypeCombinator::intersect(
+				new self(
+					TypeCombinator::union($this->keyType, $offsetType),
+					TypeCombinator::union($this->itemType, $valueType),
+				),
+				new HasOffsetValueType($offsetType, $valueType),
+				new NonEmptyArrayType()
+			);
 		}
 
-		return TypeCombinator::intersect($array, new NonEmptyArrayType());
+		return TypeCombinator::intersect(
+			new self(
+				TypeCombinator::union($this->keyType, $offsetType),
+				$unionValues ? TypeCombinator::union($this->itemType, $valueType) : $valueType,
+			),
+			new NonEmptyArrayType()
+		);
 	}
 
 	public function unsetOffset(Type $offsetType): Type