diff --git a/DEPS b/DEPS
index de57b75db248..f7b94df747de 100644
--- a/DEPS
+++ b/DEPS
@@ -123,7 +123,7 @@ vars = {
   "collection_rev": "a566328f793cd26c52f3fa4010fe331bb8700383",
   "convert_rev": "20d136c2fa4edc229fc3d7684bbeb8df5105580b",
   "crypto_rev": "f854f2fa730acb107aa41ebe431403081f7161e4",
-  "csslib_rev": "7054945b62bd83c4c7a0fab693fa73c3f137c202",
+  "csslib_rev": "f33d63211f77e2a895b90bcf22508ab7a0af4466",
   # Note: Updates to dart_style have to be coordinated with the infrastructure
   # team so that the internal formatter `tools/sdks/dart-sdk/bin/dart format`
   # matches the version here. Please follow this process to make updates:
@@ -140,7 +140,7 @@ vars = {
   "file_rev": "b768f79dcd104a5feabafab47101c4355b71cd8f",
   "fixnum_rev": "71f0d4d16054e6be7d8e22bdb3b082b9f82061be",
   "glob_rev": "4579281741e59e2e4ad02a197e0b1f4d6558dede",
-  "html_rev": "3dd00b0ca99e222697e6b6dc653774dc877da420",
+  "html_rev": "f118e004dfe68a4d101246106e775c0231efb79a",
   "http_rev": "092bb2d5ed1d522c55ef6781a469ba1e53cee2a8",
   "http_multi_server_rev": "cce50802b66d33f703f82b3189988aa8e51976ac",
   "http_parser_rev": "6f73e4a399df013ded8f4c81f151d122b36d361b",
diff --git a/tools/manage_deps.dart b/tools/manage_deps.dart
index ea77ca73a23d..d83d604f0023 100755
--- a/tools/manage_deps.dart
+++ b/tools/manage_deps.dart
@@ -117,7 +117,7 @@ This will:
       if (argResults.wasParsed('target'))
         argResults['target']
       else
-        'origin/HEAD',
+        'origin/${defaultBranchTarget(pkgDir)}',
     ], workingDirectory: pkgDir, explanation: 'Finding sha-id');
 
     final target = gitRevParseResult.first;
@@ -265,3 +265,19 @@ int runProcessForExitCode(List<String> cmd,
   stdout.writeln(' => ${result.exitCode}');
   return result.exitCode;
 }
+
+String defaultBranchTarget(String dir) {
+  var branchNames = Directory(p.join(dir, '.git', 'refs', 'heads'))
+      .listSync()
+      .whereType<File>()
+      .map((f) => p.basename(f.path))
+      .toSet();
+
+  for (var name in ['main', 'master']) {
+    if (branchNames.contains(name)) {
+      return name;
+    }
+  }
+
+  return 'HEAD';
+}
diff --git a/tools/rev_sdk_deps.dart b/tools/rev_sdk_deps.dart
index 101af05cc786..55c97259e05a 100644
--- a/tools/rev_sdk_deps.dart
+++ b/tools/rev_sdk_deps.dart
@@ -114,13 +114,13 @@ class GitHelper {
   }
 
   Future<String> findLatestUnsyncedCommit() async {
-    // git log HEAD..origin --format=%H -1
+    // git log ..origin/<default-branch> --format=%H -1
 
     var result = await exec(
       [
         'git',
         'log',
-        'HEAD..origin',
+        '..origin/$defaultBranchName',
         '--format=%H',
         '-1',
       ],
@@ -130,18 +130,34 @@ class GitHelper {
   }
 
   Future<String> calculateUnsyncedCommits() async {
-    // git log HEAD..origin --format="%h  %ad  %aN  %s" -1
+    // git log ..origin/<default-branch> --format="%h  %ad  %aN  %s" -1
     var result = await exec(
       [
         'git',
         'log',
-        'HEAD..origin',
+        '..origin/$defaultBranchName',
         '--format=%h  %ad  %aN  %s',
       ],
       cwd: dir,
     );
     return result.trim();
   }
+
+  String get defaultBranchName {
+    var branchNames = Directory(path.join(dir, '.git', 'refs', 'heads'))
+        .listSync()
+        .whereType<File>()
+        .map((f) => path.basename(f.path))
+        .toSet();
+
+    for (var name in ['main', 'master']) {
+      if (branchNames.contains(name)) {
+        return name;
+      }
+    }
+
+    return 'origin';
+  }
 }
 
 class GClientHelper {