diff --git a/common/rfb/Encoder.h b/common/rfb/Encoder.h
index 26d5796..8712c09 100644
--- a/common/rfb/Encoder.h
+++ b/common/rfb/Encoder.h
@@ -36,11 +36,10 @@
     virtual void setFineQualityLevel(int quality, int subsampling) {};
     virtual int getNumRects(const Rect &r) { return 1; }
 
-    // writeRect() tries to write the given rectangle.  If it is unable to
-    // write the whole rectangle it returns false and sets actual to the actual
-    // rectangle which was updated.
-    virtual bool writeRect(const Rect& r, TransImageGetter* ig,
-                           Rect* actual)=0;
+    // writeRect() is the main interface that encodes the given rectangle
+    // with data from the ImageGetter onto the SMsgWriter given at
+    // encoder creation.
+    virtual void writeRect(const Rect& r, TransImageGetter* ig)=0;
 
     static bool supported(int encoding);
     static Encoder* createEncoder(int encoding, SMsgWriter* writer);