diff --git a/stream/filters/slice_stream.h b/stream/filters/slice_stream.h
index d792b57d6..990092be7 100644
--- a/stream/filters/slice_stream.h
+++ b/stream/filters/slice_stream.h
@@ -55,7 +55,12 @@ class SliceStream : public Stream
   size_t size() const { return length; }
 
   const void *getPtr() { return getPtr(0, length); }
-  const void *getPtr(size_t size) { return getPtr(pos, size); }
+  const void *getPtr(size_t size)
+    {
+      void *ptr = getPtr(pos, size);
+      seek(pos+size);
+      return ptr;
+    }
   const void *getPtr(size_t pos, size_t size)
     {
       // Boundry checks on pos and size. Bounding the size is
diff --git a/stream/servers/memory_stream.h b/stream/servers/memory_stream.h
index d77779878..29bc476fc 100644
--- a/stream/servers/memory_stream.h
+++ b/stream/servers/memory_stream.h
@@ -71,9 +71,15 @@ class MemoryStream : public Stream
   size_t size() const { return length; }
   bool eof() const { return pos == length; }
 
-  /// Get the base pointer to the entire buffer
   const void *getPtr() { return data; }
-  const void *getPtr(size_t size) { return ((char*)data)+pos; }
+  const void *getPtr(size_t size)
+    {
+      // This variant of getPtr must move the position pointer
+      size_t opos = pos;
+      pos += size;
+      if(pos > length) pos = length;
+      return ((char*)data)+opos;
+    }
   const void *getPtr(size_t pos, size_t size)
     {
       if(pos > length) pos = length;
diff --git a/stream/stream.h b/stream/stream.h
index 309b0b33a..53e662341 100644
--- a/stream/stream.h
+++ b/stream/stream.h
@@ -60,13 +60,14 @@ class Stream
   /// memory-based streams where using them would be an optimization.
   virtual const void *getPtr() { assert(0); }
 
-  /// Get a pointer to a memory region of 'size' bytes from the
-  /// current position.
-  virtual const void *getPtr(size_t size) { assert(0); }
-
   /// Get a pointer to a memory region of 'size' bytes starting from
   /// position 'pos'
   virtual const void *getPtr(size_t pos, size_t size) { assert(0); }
+
+  /// Get a pointer to a memory region of 'size' bytes from the
+  /// current position. Unlike the two other getPtr variants, this
+  /// will advance the position past the returned area.
+  virtual const void *getPtr(size_t size) { assert(0); }
 };
 
 typedef boost::shared_ptr<Stream> StreamPtr;