| Index: pkg/analyzer/lib/src/dart/analysis/index.dart | 
| diff --git a/pkg/analyzer/lib/src/dart/analysis/index.dart b/pkg/analyzer/lib/src/dart/analysis/index.dart | 
| index 04d33590e43284d4e810c0c09baf8162e1326e61..f4b2139f6a8d0343fa4392bed4360de5b0f9a2ae 100644 | 
| --- a/pkg/analyzer/lib/src/dart/analysis/index.dart | 
| +++ b/pkg/analyzer/lib/src/dart/analysis/index.dart | 
| @@ -610,8 +610,10 @@ class _IndexContributor extends GeneralizingAstVisitor { | 
|  | 
| @override | 
| visitPartDirective(PartDirective node) { | 
| -    Element element = node.element; | 
| -    recordUriReference(element, node); | 
| +    CompilationUnitElement element = node.element; | 
| +    if (element?.source != null) { | 
| +      recordUriReference(element, node); | 
| +    } | 
| super.visitPartDirective(node); | 
| } | 
|  | 
|  |