diff --git a/lib/src/package_analyzer.dart b/lib/src/package_analyzer.dart
index 2074cd13a..90c0b7738 100644
--- a/lib/src/package_analyzer.dart
+++ b/lib/src/package_analyzer.dart
@@ -6,7 +6,6 @@ import 'dart:async';
 import 'dart:io';
 import 'dart:typed_data';
 
-import 'package:collection/collection.dart';
 import 'package:logging/logging.dart';
 import 'package:pana/src/tool/git_tool.dart';
 import 'package:path/path.dart' as path;
@@ -287,7 +286,7 @@ Future<AnalysisResult> _createAnalysisResult(
   final repoVerification = await context.repository;
   final repository = repoVerification?.repository;
   final fundingUrls =
-      pubspecUrls.funding.map((e) => e.verifiedUrl).whereNotNull().toList();
+      pubspecUrls.funding.map((e) => e.verifiedUrl).nonNulls.toList();
   return AnalysisResult(
     homepageUrl: pubspecUrls.homepage.verifiedUrl,
     repositoryUrl: pubspecUrls.repository.verifiedUrl,
diff --git a/lib/src/package_context.dart b/lib/src/package_context.dart
index 1ac6d3710..4951d76bb 100644
--- a/lib/src/package_context.dart
+++ b/lib/src/package_context.dart
@@ -5,7 +5,6 @@
 import 'dart:convert';
 import 'dart:io';
 
-import 'package:collection/collection.dart';
 import 'package:path/path.dart' as p;
 import 'package:pub_semver/pub_semver.dart';
 
@@ -209,7 +208,7 @@ class PackageContext {
       );
       final list = LineSplitter.split(output)
           .map((s) => parseCodeProblem(s, projectDir: packageDir))
-          .whereNotNull()
+          .nonNulls
           .toSet()
           .toList();
       list.sort();