diff --git a/src/common/buffer.cc b/src/common/buffer.cc
index 41999c7db..38eb82c8c 100644
--- a/src/common/buffer.cc
+++ b/src/common/buffer.cc
@@ -280,6 +280,11 @@ Buffer::Buffer (uint32_t dataSize, bool initialize)
 bool
 Buffer::CheckInternalState (void) const
 {
+#if 0
+  // If you want to modify any code in this file, enable this checking code.
+  // Otherwise, there is not much point is enabling it because the
+  // current implementation has been fairly seriously tested and the cost
+  // of this constant checking is pretty high, even for a debug build.
   bool offsetsOk = 
     m_start <= m_zeroAreaStart &&
     m_zeroAreaStart <= m_zeroAreaEnd &&
@@ -300,6 +305,9 @@ Buffer::CheckInternalState (void) const
                           ", " << (internalSizeOk?"true":"false") << " ");
     }
   return ok;
+#else
+  return true;
+#endif
 }
 
 void
@@ -376,13 +384,6 @@ Buffer::~Buffer ()
     }
 }
 
-uint32_t 
-Buffer::GetSize (void) const
-{
-  NS_ASSERT (CheckInternalState ());
-  return m_end - m_start;
-}
-
 Buffer::Iterator 
 Buffer::Begin (void) const
 {
diff --git a/src/common/buffer.h b/src/common/buffer.h
index 2ec401b9b..6c1a1965c 100644
--- a/src/common/buffer.h
+++ b/src/common/buffer.h
@@ -393,7 +393,7 @@ public:
   /**
    * \return the number of bytes stored in this buffer.
    */
-  uint32_t GetSize (void) const;
+  inline uint32_t GetSize (void) const;
 
   /**
    * \return a pointer to the start of the internal 
@@ -633,6 +633,11 @@ Buffer::Iterator::ReadU8 (void)
     }
 }
 
+uint32_t 
+Buffer::GetSize (void) const
+{
+  return m_end - m_start;
+}
 
 } // namespace ns3
 
diff --git a/src/common/packet.cc b/src/common/packet.cc
index 5679a0320..521f69408 100644
--- a/src/common/packet.cc
+++ b/src/common/packet.cc
@@ -225,12 +225,6 @@ Packet::GetNixVector (void) const
   return m_nixVector;
 } 
 
-uint32_t 
-Packet::GetSize (void) const
-{
-  return m_buffer.GetSize ();
-}
-
 void
 Packet::AddHeader (const Header &header)
 {
diff --git a/src/common/packet.h b/src/common/packet.h
index 94ccdbfc6..a158a088e 100644
--- a/src/common/packet.h
+++ b/src/common/packet.h
@@ -254,7 +254,7 @@ public:
    * \returns the size in bytes of the packet (including the zero-filled
    *          initial payload)
    */
-  uint32_t GetSize (void) const;
+  inline uint32_t GetSize (void) const;
   /**
    * Add header to this packet. This method invokes the
    * Header::GetSerializedSize and Header::Serialize
@@ -613,4 +613,14 @@ std::ostream& operator<< (std::ostream& os, const Packet &packet);
 
 } // namespace ns3
 
+namespace ns3 {
+
+uint32_t 
+Packet::GetSize (void) const
+{
+  return m_buffer.GetSize ();
+}
+
+} // namespace ns3
+
 #endif /* PACKET_H */