diff --git a/DEPS b/DEPS
index b7414b3d6cb..df81aaa7039 100644
--- a/DEPS
+++ b/DEPS
@@ -139,12 +139,12 @@ vars = {
   "leak_tracker_rev": "f5620600a5ce1c44f65ddaa02001e200b096e14c", # rolled manually
   "material_color_utilities_rev": "799b6ba2f3f1c28c67cc7e0b4f18e0c7d7f3c03e",
   "native_rev": "2d4b07ae9a11ede9d434dbef5cded0ad08e22e3f", # rolled manually while native assets are experimental
-  "protobuf_rev": "b7753f6fc29402679e05e9a510074002f0826d48",
+  "protobuf_rev": "deda2883eb3c8437a89bdae524b732fffef6150c",
   "pub_rev": "59406faad8959e332da98260bab894feb8500908", # rolled manually
   "shelf_rev": "082d3ac2d13a98700d8148e8fad8f3e12a6fd0e1",
   "sync_http_rev": "dc54465f07d9652875deeade643256dafa2fbc6c",
   "tar_rev": "5a1ea943e70cdf3fa5e1102cdbb9418bd9b4b81a",
-  "test_rev": "b9c59ea01ab0c055d120fd6542af663704c16938",
+  "test_rev": "5ffcb36fd6c82843f25ed96585a4b9e96022e7f9",
   "tools_rev": "36f5c9f9989e06e79323499914c50e78ab1a6621",
   "vector_math_rev": "13f185f7e97d559e003f5ac79201da12f9a01049",
   "web_rev": "f1becf07db9faa56559d2844c3c6d430dc9b37de",
diff --git a/pkg/vm_service_protos/pubspec.yaml b/pkg/vm_service_protos/pubspec.yaml
index 5a22cb36bfd..357843e4ca6 100644
--- a/pkg/vm_service_protos/pubspec.yaml
+++ b/pkg/vm_service_protos/pubspec.yaml
@@ -13,7 +13,7 @@ resolution: workspace
 
 dependencies:
   fixnum: ^1.0.0
-  protobuf: ">=4.0.0 <5.0.0"
+  protobuf: ^4.0.0
 
 # We use 'any' version constraints here as we get our package versions from
 # the dart-lang/sdk repo's DEPS file. Note that this is a special case; the
diff --git a/tools/package_deps/bin/package_deps.dart b/tools/package_deps/bin/package_deps.dart
index f3876492209..c996d8982e5 100644
--- a/tools/package_deps/bin/package_deps.dart
+++ b/tools/package_deps/bin/package_deps.dart
@@ -193,13 +193,6 @@ class Package implements Comparable<Package> {
     var devdeps = devDependencies;
     devdeps.remove(packageName);
 
-    // if (deps.isNotEmpty) {
-    //   print('  deps    : ${deps}');
-    // }
-    // if (devdeps.isNotEmpty) {
-    //   print('  dev deps: ${devdeps}');
-    // }
-
     void out(String message) {
       logger.stdout(logger.ansi.emphasized(message));
     }
@@ -467,22 +460,35 @@ class SdkDeps {
 
   void _findPackages(Directory dir) {
     var pubspec = File(path.join(dir.path, 'pubspec.yaml'));
+
     if (pubspec.existsSync()) {
       var doc = yaml.loadYamlDocument(pubspec.readAsStringSync());
-      var contents = doc.contents as yaml.YamlMap;
-      var name = contents['name'];
-      var version = contents['version'];
-      var dep = ResolvedDep(
-        packageName: name,
-        relativePath: path.relative(dir.path),
-        version: version == null ? null : Version.parse(version),
-      );
-      _resolvedPackageVersions[name] = dep;
-    } else {
-      // Continue to recurse.
-      for (var subDir in dir.listSync().whereType<Directory>()) {
-        _findPackages(subDir);
+      if (doc.contents is! yaml.YamlMap) {
+        // Stop recursing.
+        return;
       }
+
+      var contents = doc.contents as yaml.YamlMap;
+      final isWorkspace = contents.containsKey('workspace');
+
+      if (!isWorkspace) {
+        var name = contents['name'];
+        var version = contents['version'];
+        var dep = ResolvedDep(
+          packageName: name,
+          relativePath: path.relative(dir.path),
+          version: version == null ? null : Version.parse(version),
+        );
+        _resolvedPackageVersions[name] = dep;
+
+        // We've found a leaf package - stop recursing.
+        return;
+      }
+    }
+
+    // Continue to recurse.
+    for (var subDir in dir.listSync().whereType<Directory>()) {
+      _findPackages(subDir);
     }
   }
 }