diff --git a/src/google/protobuf/compiler/cpp/cpp_field.h b/src/google/protobuf/compiler/cpp/cpp_field.h
index 96c29633..0342c35e 100644
--- a/src/google/protobuf/compiler/cpp/cpp_field.h
+++ b/src/google/protobuf/compiler/cpp/cpp_field.h
@@ -77,7 +77,7 @@ class FieldGenerator {
   // Generate static default variable for this field. These are placed inside
   // the message class. Most field types don't need this, so the default
   // implementation is empty.
-  virtual void GenerateStaticMembers(io::Printer* printer) const {}
+  virtual void GenerateStaticMembers(io::Printer* /*printer*/) const {}
 
   // Generate prototypes for all of the accessor functions related to this
   // field.  These are placed inside the class definition.
@@ -92,7 +92,7 @@ class FieldGenerator {
   // placed somewhere in the .cc file.
   // Most field types don't need this, so the default implementation is empty.
   virtual void GenerateNonInlineAccessorDefinitions(
-    io::Printer* printer) const {}
+    io::Printer* /*printer*/) const {}
 
   // Generate lines of code (statements, not declarations) which clear the
   // field.  This is used to define the clear_$name$() method as well as
@@ -122,14 +122,15 @@ class FieldGenerator {
   // Generate any code that needs to go in the class's SharedDtor() method,
   // invoked by the destructor.
   // Most field types don't need this, so the default implementation is empty.
-  virtual void GenerateDestructorCode(io::Printer* printer) const {}
+  virtual void GenerateDestructorCode(io::Printer* /*printer*/) const {}
 
   // Generate code that allocates the fields's default instance.
-  virtual void GenerateDefaultInstanceAllocator(io::Printer* printer) const {}
+  virtual void GenerateDefaultInstanceAllocator(io::Printer* /*printer*/)
+      const {}
 
   // Generate code that should be run when ShutdownProtobufLibrary() is called,
   // to delete all dynamically-allocated objects.
-  virtual void GenerateShutdownCode(io::Printer* printer) const {}
+  virtual void GenerateShutdownCode(io::Printer* /*printer*/) const {}
 
   // Generate lines to decode this field, which will be placed inside the
   // message's MergeFromCodedStream() method.
diff --git a/src/google/protobuf/descriptor.h b/src/google/protobuf/descriptor.h
index 67afc774..68013f8e 100644
--- a/src/google/protobuf/descriptor.h
+++ b/src/google/protobuf/descriptor.h
@@ -1280,11 +1280,11 @@ class LIBPROTOBUF_EXPORT DescriptorPool {
     // Reports a warning in the FileDescriptorProto. Use this function if the
     // problem occured should NOT interrupt building the FileDescriptorProto.
     virtual void AddWarning(
-      const string& filename,      // File name in which the error occurred.
-      const string& element_name,  // Full name of the erroneous element.
-      const Message* descriptor,   // Descriptor of the erroneous element.
-      ErrorLocation location,      // One of the location constants, above.
-      const string& message        // Human-readable error message.
+      const string& /*filename*/,      // File name in which the error occurred.
+      const string& /*element_name*/,  // Full name of the erroneous element.
+      const Message* /*descriptor*/,   // Descriptor of the erroneous element.
+      ErrorLocation /*location*/,      // One of the location constants, above.
+      const string& /*message*/        // Human-readable error message.
       ) {}
 
    private:
diff --git a/src/google/protobuf/message.h b/src/google/protobuf/message.h
index 95935605..67d45493 100644
--- a/src/google/protobuf/message.h
+++ b/src/google/protobuf/message.h
@@ -389,19 +389,19 @@ class LIBPROTOBUF_EXPORT Reflection {
   // is set, false otherwise.
   // TODO(jieluo) - make it pure virtual after updating all
   // the subclasses.
-  virtual bool HasOneof(const Message& message,
-                        const OneofDescriptor* oneof_descriptor) const {
+  virtual bool HasOneof(const Message& /*message*/,
+                        const OneofDescriptor* /*oneof_descriptor*/) const {
     return false;
   }
 
-  virtual void ClearOneof(Message* message,
-                          const OneofDescriptor* oneof_descriptor) const {}
+  virtual void ClearOneof(Message* /*message*/,
+                          const OneofDescriptor* /*oneof_descriptor*/) const {}
 
   // Returns the field descriptor if the oneof is set. NULL otherwise.
   // TODO(jieluo) - make it pure virtual.
   virtual const FieldDescriptor* GetOneofFieldDescriptor(
-      const Message& message,
-      const OneofDescriptor* oneof_descriptor) const {
+      const Message& /*message*/,
+      const OneofDescriptor* /*oneof_descriptor*/) const {
     return NULL;
   }
 
diff --git a/src/google/protobuf/repeated_field.h b/src/google/protobuf/repeated_field.h
index 50051831..816ea684 100644
--- a/src/google/protobuf/repeated_field.h
+++ b/src/google/protobuf/repeated_field.h
@@ -83,7 +83,8 @@ inline int CalculateReserve(Iter begin, Iter end, std::forward_iterator_tag) {
 }
 
 template <typename Iter>
-inline int CalculateReserve(Iter begin, Iter end, std::input_iterator_tag) {
+inline int CalculateReserve(Iter /*begin*/, Iter /*end*/,
+                            std::input_iterator_tag) {
   return -1;
 }