diff --git a/codegen/src/main/scala/org/apache/pekko/grpc/gen/CodeGenerator.scala b/codegen/src/main/scala/org/apache/pekko/grpc/gen/CodeGenerator.scala
index 5e758e4d..0859ce79 100644
--- a/codegen/src/main/scala/org/apache/pekko/grpc/gen/CodeGenerator.scala
+++ b/codegen/src/main/scala/org/apache/pekko/grpc/gen/CodeGenerator.scala
@@ -13,7 +13,6 @@
 
 package org.apache.pekko.grpc.gen
 
-import scala.annotation.nowarn
 import com.google.protobuf.ExtensionRegistry
 import com.google.protobuf.compiler.PluginProtos.CodeGeneratorRequest
 import com.google.protobuf.compiler.PluginProtos.CodeGeneratorResponse
@@ -33,7 +32,7 @@ trait CodeGenerator {
   /** Takes Scala binary version and returns suggested dependency Seq */
   def suggestedDependencies: ScalaBinaryVersion => Seq[Artifact]
 
-  def registerExtensions(@nowarn("msg=is never used") registry: ExtensionRegistry): Unit = {}
+  def registerExtensions(registry: ExtensionRegistry): Unit = {}
 
   final def run(request: Array[Byte], logger: Logger): Array[Byte] = {
     val registry = ExtensionRegistry.newInstance
diff --git a/project/Common.scala b/project/Common.scala
index 82ba63cc..45ca9d56 100644
--- a/project/Common.scala
+++ b/project/Common.scala
@@ -67,6 +67,9 @@ object Common extends AutoPlugin {
          Seq(
            // Generated code for methods/fields marked 'deprecated'
            "-Wconf:msg=Marked as deprecated in proto file:silent",
+           // Suppress "parameter X is never used" in CodeGenerator's registerExtensions
+           // default trait impl. Uses precise path+msg filter to avoid masking real warnings.
+           "-Wconf:src=.*/grpc/gen/CodeGenerator\\.scala:msg=is never used:silent",
            // ignore imports in templates (FIXME why is that trailing .* needed?)
            "-Wconf:src=.*.txt.*:silent",
            "-Wconf:cat=unused-nowarn:silent")