diff --git a/src/Claim/Claims.php b/src/Claim/Claims.php
index ba2f6d84..415517b8 100644
--- a/src/Claim/Claims.php
+++ b/src/Claim/Claims.php
@@ -2,12 +2,13 @@
 
 namespace Wikibase\DataModel\Claim;
 
+use ArrayAccess;
 use ArrayObject;
 use Comparable;
 use Hashable;
 use InvalidArgumentException;
 use Traversable;
-use Wikibase\DataModel\ByPropertyIdArray;
+use Wikibase\DataModel\ByPropertyIdGrouper;
 use Wikibase\DataModel\Entity\PropertyId;
 use Wikibase\DataModel\Snak\Snak;
 
@@ -317,14 +318,13 @@ public function getGuids() {
 	 * @return Claims
 	 */
 	public function getClaimsForProperty( PropertyId $propertyId ) {
-		$claimsByProp = new ByPropertyIdArray( $this );
-		$claimsByProp->buildIndex();
+		$byPropertyIdGrouper = new ByPropertyIdGrouper( $this );
 
-		if ( !( in_array( $propertyId, $claimsByProp->getPropertyIds() ) ) ) {
+		if ( !$byPropertyIdGrouper->hasPropertyId( $propertyId ) ) {
 			return new self();
 		}
 
-		return new self( $claimsByProp->getByPropertyId( $propertyId ) );
+		return new self( $byPropertyIdGrouper->getByPropertyId( $propertyId ) );
 	}
 
 	/**
diff --git a/tests/unit/Claim/ClaimsTest.php b/tests/unit/Claim/ClaimsTest.php
index cef8124c..26e281a0 100644
--- a/tests/unit/Claim/ClaimsTest.php
+++ b/tests/unit/Claim/ClaimsTest.php
@@ -2,25 +2,16 @@
 
 namespace Wikibase\Test;
 
-use DataValues\StringValue;
-use Diff\DiffOp\Diff\Diff;
-use Diff\DiffOp\DiffOpAdd;
-use Diff\DiffOp\DiffOpChange;
-use Diff\DiffOp\DiffOpRemove;
 use InvalidArgumentException;
 use ReflectionClass;
-use Wikibase\DataModel\ByPropertyIdArray;
 use Wikibase\DataModel\Claim\Claim;
+use Wikibase\DataModel\Claim\ClaimList;
 use Wikibase\DataModel\Claim\Claims;
-use Wikibase\DataModel\Statement\Statement;
 use Wikibase\DataModel\Entity\PropertyId;
-use Wikibase\DataModel\Reference;
-use Wikibase\DataModel\ReferenceList;
 use Wikibase\DataModel\Snak\PropertyNoValueSnak;
 use Wikibase\DataModel\Snak\PropertySomeValueSnak;
-use Wikibase\DataModel\Snak\PropertyValueSnak;
 use Wikibase\DataModel\Snak\Snak;
-use Wikibase\DataModel\Snak\SnakList;
+use Wikibase\DataModel\Statement\Statement;
 
 /**
  * @covers Wikibase\DataModel\Claim\Claims
@@ -66,10 +57,10 @@ public function testArrayObjectNotConstructedFromObject() {
 		$claim1 = $this->makeClaim( new PropertyNoValueSnak( 1 ) );
 		$claim2 = $this->makeClaim( new PropertyNoValueSnak( 2 ) );
 
-		$byPropertyIdArray = new ByPropertyIdArray();
-		$byPropertyIdArray->append( $claim1 );
+		$claimList = new ClaimList();
+		$claimList->addClaim( $claim1 );
 
-		$claims = new Claims( $byPropertyIdArray );
+		$claims = new Claims( $claimList );
 		// According to the documentation append() "cannot be called when the ArrayObject was
 		// constructed from an object." This test makes sure it was not constructed from an object.
 		$claims->append( $claim2 );