diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 78deccd3e..dde870bb5 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -7104,7 +7104,11 @@ FurnaceGUI::FurnaceGUI():
   sampleSelStart(-1),
   sampleSelEnd(-1),
   sampleDragActive(false),
-  sampleDragMode(false) {
+  sampleDragMode(false),
+  sampleDrag16(false),
+  sampleDragTarget(NULL),
+  sampleDragStart(0,0),
+  sampleDragAreaSize(0,0) {
 
   // octave 1
   /*
diff --git a/src/gui/gui.h b/src/gui/gui.h
index 568ea8ed0..0edbea956 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -743,7 +743,10 @@ class FurnaceGUI {
   int resampleStrat;
   float amplifyVol;
   int sampleSelStart, sampleSelEnd;
-  bool sampleDragActive, sampleDragMode;
+  bool sampleDragActive, sampleDragMode, sampleDrag16;
+  void* sampleDragTarget;
+  ImVec2 sampleDragStart;
+  ImVec2 sampleDragAreaSize;
 
   // visualizer
   float keyHit[DIV_MAX_CHANS];