diff --git a/example/googleapis/pubspec.yaml b/example/googleapis/pubspec.yaml
index 3430ceaf..9d3bdf10 100644
--- a/example/googleapis/pubspec.yaml
+++ b/example/googleapis/pubspec.yaml
@@ -11,7 +11,7 @@ dependencies:
   async: any
   fixnum: any
   grpc: any
-  protobuf: any
+  protobuf: ">=5.1.0 <7.0.0"
 
 dev_dependencies:
   lints: ^6.0.0
diff --git a/example/grpc-web/pubspec.yaml b/example/grpc-web/pubspec.yaml
index 289b7c4a..8a0e1e30 100644
--- a/example/grpc-web/pubspec.yaml
+++ b/example/grpc-web/pubspec.yaml
@@ -9,7 +9,7 @@ environment:
 
 dependencies:
   grpc: any
-  protobuf: any
+  protobuf: ">=5.1.0 <7.0.0"
   web: any
 
 dev_dependencies:
diff --git a/example/helloworld/pubspec.yaml b/example/helloworld/pubspec.yaml
index 2941dcea..baa4c8f7 100644
--- a/example/helloworld/pubspec.yaml
+++ b/example/helloworld/pubspec.yaml
@@ -10,7 +10,7 @@ environment:
 dependencies:
   async: any
   grpc: any
-  protobuf: any
+  protobuf: ">=5.1.0 <7.0.0"
 
 dev_dependencies:
   lints: ^6.0.0
diff --git a/example/metadata/pubspec.yaml b/example/metadata/pubspec.yaml
index bf2f6f51..182e3ccb 100644
--- a/example/metadata/pubspec.yaml
+++ b/example/metadata/pubspec.yaml
@@ -10,7 +10,7 @@ environment:
 dependencies:
   async: any
   grpc: any
-  protobuf: any
+  protobuf: ">=5.1.0 <7.0.0"
 
 dev_dependencies:
   lints: ^6.0.0
diff --git a/example/route_guide/pubspec.yaml b/example/route_guide/pubspec.yaml
index 33baa739..314978b5 100644
--- a/example/route_guide/pubspec.yaml
+++ b/example/route_guide/pubspec.yaml
@@ -11,7 +11,7 @@ dependencies:
   async: any
   collection: any
   grpc: any
-  protobuf: any
+  protobuf: ">=5.1.0 <7.0.0"
 
 dev_dependencies:
   lints: ^6.0.0
diff --git a/interop/pubspec.yaml b/interop/pubspec.yaml
index 1d459dda..ba449be5 100644
--- a/interop/pubspec.yaml
+++ b/interop/pubspec.yaml
@@ -12,7 +12,7 @@ dependencies:
   async: any
   collection: any
   grpc: any
-  protobuf: any
+  protobuf: ">=5.1.0 <7.0.0"
 
 dev_dependencies:
   lints: ^6.0.0
diff --git a/pubspec.yaml b/pubspec.yaml
index c3350ed7..a54bfc48 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -27,7 +27,7 @@ dependencies:
   meta: ^1.16.0
   http: ^1.4.0
   http2: ^2.3.1
-  protobuf: ^5.1.0
+  protobuf: ">=5.1.0 <7.0.0"
   clock: ^1.1.2
   web: ^1.1.1