diff --git a/Sources/GRPCProtobufCodeGen/ProtobufCodeGenParser.swift b/Sources/GRPCProtobufCodeGen/ProtobufCodeGenParser.swift
index dfddec6..00a2e90 100644
--- a/Sources/GRPCProtobufCodeGen/ProtobufCodeGenParser.swift
+++ b/Sources/GRPCProtobufCodeGen/ProtobufCodeGenParser.swift
@@ -110,15 +110,26 @@ extension ProtobufCodeGenParser {
     var codeDependencies: [Dependency] = [
       Dependency(module: self.moduleNames.grpcProtobuf, accessLevel: .internal)
     ]
+
     // If there's a dependency on a bundled proto then add the SwiftProtobuf import.
     //
     // Importing SwiftProtobuf unconditionally results in warnings in the generated
     // code if access-levels are used on imports and no bundled protos are used.
-    let dependsOnBundledProto = file.dependencies.contains { descriptor in
-      SwiftProtobufInfo.isBundledProto(file: descriptor)
+    //
+    // The import is only needed if a bundled proto is used as the input or output type
+    // for an RPC. The file may have a dependency on a bundled proto without requiring
+    // the SwiftProtobuf import (e.g. a message depending on a bundle proto may be
+    // defined in the same file as the service, the dependency will be in the '.pb.swift'
+    // along with the message code).
+    let needsProtobufImport = file.services.contains { service in
+      service.methods.contains { method in
+        let inputIsBundled = SwiftProtobufInfo.isBundledProto(file: method.inputType.file)
+        let outputIsBundled = SwiftProtobufInfo.isBundledProto(file: method.outputType.file)
+        return inputIsBundled || outputIsBundled
+      }
     }
 
-    if dependsOnBundledProto {
+    if needsProtobufImport {
       let dependency = Dependency(
         module: self.moduleNames.swiftProtobuf,
         accessLevel: self.accessLevel
diff --git a/Sources/protoc-gen-grpc-swift-2/Options.swift b/Sources/protoc-gen-grpc-swift-2/Options.swift
index a068a53..6c82334 100644
--- a/Sources/protoc-gen-grpc-swift-2/Options.swift
+++ b/Sources/protoc-gen-grpc-swift-2/Options.swift
@@ -62,6 +62,8 @@ struct GeneratorOptions {
   }
 
   init(pairs: [(key: String, value: String)]) throws {
+    var moduleMapPath: String?
+
     for pair in pairs {
       switch pair.key {
       case "Visibility":
@@ -87,14 +89,7 @@ struct GeneratorOptions {
 
       case "ProtoPathModuleMappings":
         if !pair.value.isEmpty {
-          do {
-            self.protoToModuleMappings = try ProtoFileToModuleMappings(path: pair.value)
-          } catch let e {
-            throw GenerationError.wrappedError(
-              message: "Parameter 'ProtoPathModuleMappings=\(pair.value)'",
-              error: e
-            )
-          }
+          moduleMapPath = pair.value
         }
 
       case "FileNaming":
@@ -164,6 +159,24 @@ struct GeneratorOptions {
         throw GenerationError.unknownParameter(name: pair.key)
       }
     }
+
+    if let moduleMapPath = moduleMapPath {
+      do {
+        self.protoToModuleMappings = try ProtoFileToModuleMappings(
+          path: moduleMapPath,
+          swiftProtobufModuleName: self.config.moduleNames.swiftProtobuf
+        )
+      } catch let e {
+        throw GenerationError.wrappedError(
+          message: "Parameter 'ProtoPathModuleMappings=\(moduleMapPath)'",
+          error: e
+        )
+      }
+    } else {
+      self.protoToModuleMappings = ProtoFileToModuleMappings(
+        swiftProtobufModuleName: self.config.moduleNames.swiftProtobuf
+      )
+    }
   }
 
   static func parseParameter(string: String?) -> [(key: String, value: String)] {
diff --git a/Tests/GRPCProtobufCodeGenTests/Generated/test-service.pb b/Tests/GRPCProtobufCodeGenTests/Generated/test-service.pb
index 507373b..58866e2 100644
Binary files a/Tests/GRPCProtobufCodeGenTests/Generated/test-service.pb and b/Tests/GRPCProtobufCodeGenTests/Generated/test-service.pb differ
diff --git a/Tests/GRPCProtobufCodeGenTests/ProtobufCodeGenParserTests.swift b/Tests/GRPCProtobufCodeGenTests/ProtobufCodeGenParserTests.swift
index 4c31520..99ad2e9 100644
--- a/Tests/GRPCProtobufCodeGenTests/ProtobufCodeGenParserTests.swift
+++ b/Tests/GRPCProtobufCodeGenTests/ProtobufCodeGenParserTests.swift
@@ -66,8 +66,7 @@ struct ProtobufCodeGenParserTests {
     @available(gRPCSwiftProtobuf 2.0, *)
     func dependencies() throws {
       let expected: [GRPCCodeGen.Dependency] = [
-        .init(module: "GRPCProtobuf", accessLevel: .internal),  // Always an internal import
-        .init(module: "SwiftProtobuf", accessLevel: .internal),
+        .init(module: "GRPCProtobuf", accessLevel: .internal)  // Always an internal import
       ]
       #expect(try self.codeGen.dependencies == expected)
     }
@@ -266,5 +265,37 @@ struct ProtobufCodeGenParserTests {
       ]
       #expect(codeGen.dependencies == expected)
     }
+
+    @Test("Generate with different module names")
+    @available(gRPCSwiftProtobuf 2.0, *)
+    func generateWithDifferentModuleNames() throws {
+      var config = ProtobufCodeGenerator.Config.defaults
+      let defaultNames = config.moduleNames
+
+      config.accessLevel = .public
+      config.indentation = 2
+      config.moduleNames.grpcCore = String(config.moduleNames.grpcCore.reversed())
+      config.moduleNames.grpcProtobuf = String(config.moduleNames.grpcProtobuf.reversed())
+      config.moduleNames.swiftProtobuf = String(config.moduleNames.swiftProtobuf.reversed())
+
+      let generator = ProtobufCodeGenerator(config: config)
+      let generated = try generator.generateCode(
+        fileDescriptor: Self.fileDescriptor,
+        protoFileModuleMappings: ProtoFileToModuleMappings(
+          swiftProtobufModuleName: config.moduleNames.swiftProtobuf
+        ),
+        extraModuleImports: []
+      )
+
+      // Mustn't contain the default names.
+      #expect(!generated.contains(defaultNames.grpcCore))
+      #expect(!generated.contains(defaultNames.grpcProtobuf))
+      #expect(!generated.contains(defaultNames.swiftProtobuf))
+
+      // Must contain the configured names.
+      #expect(generated.contains(config.moduleNames.grpcCore))
+      #expect(generated.contains(config.moduleNames.grpcProtobuf))
+      #expect(generated.contains(config.moduleNames.swiftProtobuf))
+    }
   }
 }
diff --git a/Tests/GRPCProtobufCodeGenTests/ProtobufCodeGeneratorTests.swift b/Tests/GRPCProtobufCodeGenTests/ProtobufCodeGeneratorTests.swift
index c4fdc62..1a85158 100644
--- a/Tests/GRPCProtobufCodeGenTests/ProtobufCodeGeneratorTests.swift
+++ b/Tests/GRPCProtobufCodeGenTests/ProtobufCodeGeneratorTests.swift
@@ -99,7 +99,6 @@ struct ProtobufCodeGeneratorTests {
 
         import GRPCCore
         import GRPCProtobuf
-        import SwiftProtobuf
 
         // MARK: - test.TestService
 
@@ -1103,35 +1102,6 @@ struct ProtobufCodeGeneratorTests {
       #expect(generated == expected)
     }
 
-    @Test("Generate with different module names")
-    @available(gRPCSwiftProtobuf 2.0, *)
-    func generateWithDifferentModuleNames() throws {
-      var config = ProtobufCodeGenerator.Config.defaults
-      let defaultNames = config.moduleNames
-
-      config.accessLevel = .public
-      config.indentation = 2
-      config.moduleNames.grpcCore = String(config.moduleNames.grpcCore.reversed())
-      config.moduleNames.grpcProtobuf = String(config.moduleNames.grpcProtobuf.reversed())
-      config.moduleNames.swiftProtobuf = String(config.moduleNames.swiftProtobuf.reversed())
-
-      let generator = ProtobufCodeGenerator(config: config)
-      let generated = try generator.generateCode(
-        fileDescriptor: Self.fileDescriptor,
-        protoFileModuleMappings: ProtoFileToModuleMappings(),
-        extraModuleImports: []
-      )
-
-      // Mustn't contain the default names.
-      #expect(!generated.contains(defaultNames.grpcCore))
-      #expect(!generated.contains(defaultNames.grpcProtobuf))
-      #expect(!generated.contains(defaultNames.swiftProtobuf))
-
-      // Must contain the configured names.
-      #expect(generated.contains(config.moduleNames.grpcCore))
-      #expect(generated.contains(config.moduleNames.grpcProtobuf))
-      #expect(generated.contains(config.moduleNames.swiftProtobuf))
-    }
   }
 
   @Suite("File-without-services (foo-messages.proto)")
diff --git a/dev/protos/local/test-service.proto b/dev/protos/local/test-service.proto
index 2ff7430..aaf6a66 100644
--- a/dev/protos/local/test-service.proto
+++ b/dev/protos/local/test-service.proto
@@ -3,7 +3,7 @@ syntax = "proto3";
 
 package test;
 
-// Using a WKT forces an "SwiftProtobuf" to be imported in generated code.
+// WKT isn't used in API generated by gRPC, so no import is expected.
 import "google/protobuf/any.proto";
 
 // Service docs.