diff --git a/Svrnty.CQRS.Grpc.Generators/WriteProtoFileTask.cs b/Svrnty.CQRS.Grpc.Generators/WriteProtoFileTask.cs
index 3650f86..894b1c6 100644
--- a/Svrnty.CQRS.Grpc.Generators/WriteProtoFileTask.cs
+++ b/Svrnty.CQRS.Grpc.Generators/WriteProtoFileTask.cs
@@ -67,6 +67,16 @@ public class WriteProtoFileTask : Task
                 "GeneratedProtoFile.g.cs"
             );
 
+            // Check if proto file already exists (committed to repo or from previous build)
+            var existingProtoPath = Path.Combine(ProjectDirectory, OutputDirectory, ProtoFileName);
+            if (File.Exists(existingProtoPath) && !File.Exists(generatedFilePath))
+            {
+                Log.LogMessage(MessageImportance.High,
+                    $"Svrnty.CQRS.Grpc: Using existing proto file at {existingProtoPath}. " +
+                    "To regenerate, delete the file and build twice.");
+                return true;
+            }
+
             if (!File.Exists(generatedFilePath))
             {
                 Log.LogWarning(