diff --git a/src/engine/sample.cpp b/src/engine/sample.cpp
index d5e1844c8..5fab8b2b7 100644
--- a/src/engine/sample.cpp
+++ b/src/engine/sample.cpp
@@ -790,7 +790,7 @@ unsigned int DivSample::getCurBufLen() {
   return 0;
 }
 
-DivSampleHistory* DivSample::prepareUndo(bool data) {
+DivSampleHistory* DivSample::prepareUndo(bool data, bool doNotPush) {
   DivSampleHistory* h;
   if (data) {
     unsigned char* duplicate;
@@ -804,33 +804,77 @@ DivSampleHistory* DivSample::prepareUndo(bool data) {
   } else {
     h=new DivSampleHistory(depth,rate,centerRate,loopStart);
   }
-  while (!redoHist.empty()) {
-    DivSampleHistory* h=redoHist.front();
-    delete h;
-    redoHist.pop_front();
+  if (!doNotPush) {
+    while (!redoHist.empty()) {
+      DivSampleHistory* h=redoHist.back();
+      delete h;
+      redoHist.pop_back();
+    }
+    if (undoHist.size()>100) undoHist.pop_front();
+    undoHist.push_back(h);
   }
-  undoHist.push_back(h);
   return h;
 }
 
+#define applyHistory \
+  depth=h->depth; \
+  if (h->hasSample) { \
+    initInternal(h->depth,h->samples); \
+    samples=h->samples; \
+\
+    if (h->length!=getCurBufLen()) logW("undo buffer length not equal to current buffer length! %d != %d\n",h->length,getCurBufLen()); \
+\
+    void* buf=getCurBuf(); \
+\
+    if (buf!=NULL && h->data!=NULL) { \
+      memcpy(buf,h->data,h->length); \
+    } \
+  } \
+  rate=h->rate; \
+  centerRate=h->centerRate; \
+  loopStart=h->loopStart;
+
+
 int DivSample::undo() {
-  return 0;
+  if (undoHist.empty()) return 0;
+  DivSampleHistory* h=undoHist.back();
+  DivSampleHistory* redo=prepareUndo(h->hasSample,true);
+
+  int ret=h->hasSample?2:1;
+
+  applyHistory;
+
+  redoHist.push_back(redo);
+  delete h;
+  undoHist.pop_back();
+  return ret;
 }
 
 int DivSample::redo() {
-  return 0;
+  if (redoHist.empty()) return 0;
+  DivSampleHistory* h=redoHist.back();
+  DivSampleHistory* undo=prepareUndo(h->hasSample,true);
+
+  int ret=h->hasSample?2:1;
+
+  applyHistory;
+
+  undoHist.push_back(undo);
+  delete h;
+  redoHist.pop_back();
+  return ret;
 }
 
 DivSample::~DivSample() {
   while (!undoHist.empty()) {
-    DivSampleHistory* h=undoHist.front();
+    DivSampleHistory* h=undoHist.back();
     delete h;
-    undoHist.pop_front();
+    undoHist.pop_back();
   }
   while (!redoHist.empty()) {
-    DivSampleHistory* h=redoHist.front();
+    DivSampleHistory* h=redoHist.back();
     delete h;
-    redoHist.pop_front();
+    redoHist.pop_back();
   }
   if (data8) delete[] data8;
   if (data16) delete[] data16;
diff --git a/src/engine/sample.h b/src/engine/sample.h
index f07c7ef91..1a9e53d32 100644
--- a/src/engine/sample.h
+++ b/src/engine/sample.h
@@ -189,9 +189,10 @@ struct DivSample {
   /**
    * prepare an undo step for this sample.
    * @param data whether to include sample data.
+   * @param doNotPush if this is true, don't push the DivSampleHistory to the undo history.
    * @return the undo step.
    */
-  DivSampleHistory* prepareUndo(bool data);
+  DivSampleHistory* prepareUndo(bool data, bool doNotPush=false);
 
   /**
    * undo. you may need to call DivEngine::renderSamples afterwards.
diff --git a/src/gui/doAction.cpp b/src/gui/doAction.cpp
index 66a05fb3a..3866624ac 100644
--- a/src/gui/doAction.cpp
+++ b/src/gui/doAction.cpp
@@ -55,10 +55,18 @@ void FurnaceGUI::doAction(int what) {
       openFileDialog(GUI_FILE_SAVE);
       break;
     case GUI_ACTION_UNDO:
-      doUndo();
+      if (curWindow==GUI_WINDOW_SAMPLE_EDIT) {
+        doUndoSample();
+      } else {
+        doUndo();
+      }
       break;
     case GUI_ACTION_REDO:
-      doRedo();
+      if (curWindow==GUI_WINDOW_SAMPLE_EDIT) {
+        doRedoSample();
+      } else {
+        doRedo();
+      }
       break;
     case GUI_ACTION_PLAY_TOGGLE:
       if (e->isPlaying() && !e->isStepping()) {
@@ -594,6 +602,8 @@ void FurnaceGUI::doAction(int what) {
 
       if (end-start<1) break;
 
+      sample->prepareUndo(true);
+
       if (sampleClipboard!=NULL) {
         delete[] sampleClipboard;
       }
@@ -632,6 +642,7 @@ void FurnaceGUI::doAction(int what) {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       if (sampleClipboard==NULL || sampleClipboardLen<1) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       int pos=(sampleSelStart==-1 || sampleSelStart==sampleSelEnd)?sample->samples:sampleSelStart;
 
       e->lockEngine([this,sample,pos]() {
@@ -658,6 +669,7 @@ void FurnaceGUI::doAction(int what) {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       if (sampleClipboard==NULL || sampleClipboardLen<1) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       int pos=(sampleSelStart==-1 || sampleSelStart==sampleSelEnd)?0:sampleSelStart;
 
       e->lockEngine([this,sample,pos]() {
@@ -685,6 +697,7 @@ void FurnaceGUI::doAction(int what) {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       if (sampleClipboard==NULL || sampleClipboardLen<1) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       int pos=(sampleSelStart==-1 || sampleSelStart==sampleSelEnd)?0:sampleSelStart;
 
       e->lockEngine([this,sample,pos]() {
@@ -737,6 +750,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_NORMALIZE: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
         float maxVal=0.0f;
@@ -783,6 +797,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_FADE_IN: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
 
@@ -812,6 +827,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_FADE_OUT: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
 
@@ -845,6 +861,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_SILENCE: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
 
@@ -868,6 +885,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_DELETE: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
 
@@ -884,6 +902,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_TRIM: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
 
@@ -900,6 +919,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_REVERSE: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
 
@@ -931,6 +951,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_INVERT: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
 
@@ -956,6 +977,7 @@ void FurnaceGUI::doAction(int what) {
     case GUI_ACTION_SAMPLE_SIGN: {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
+      sample->prepareUndo(true);
       e->lockEngine([this,sample]() {
         SAMPLE_OP_BEGIN;
 
diff --git a/src/gui/gui.h b/src/gui/gui.h
index a4feed9b5..315ce7421 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -897,6 +897,9 @@ class FurnaceGUI {
   void doRedo();
   void editOptions(bool topMenu);
 
+  void doUndoSample();
+  void doRedoSample();
+
   void play(int row=0);
   void stop();
 
diff --git a/src/gui/sampleEdit.cpp b/src/gui/sampleEdit.cpp
index 3bdfa6c9f..0998856cc 100644
--- a/src/gui/sampleEdit.cpp
+++ b/src/gui/sampleEdit.cpp
@@ -63,14 +63,12 @@ void FurnaceGUI::drawSampleEdit() {
           for (int i=0; i<17; i++) {
             if (sampleDepths[i]==NULL) continue;
             if (ImGui::Selectable(sampleDepths[i])) {
+              sample->prepareUndo(true);
               sample->depth=i;
               e->renderSamplesP();
               updateSampleTex=true;
               MARK_MODIFIED;
             }
-            if (ImGui::IsItemHovered()) {
-              ImGui::SetTooltip("no undo for sample type change operations!");
-            }
           }
           ImGui::EndCombo();
         }
@@ -163,6 +161,7 @@ void FurnaceGUI::drawSampleEdit() {
           if (resizeSize>16777215) resizeSize=16777215;
         }
         if (ImGui::Button("Resize")) {
+          sample->prepareUndo(true);
           e->lockEngine([this,sample]() {
             if (!sample->resize(resizeSize)) {
               showError("couldn't resize! make sure your sample is 8 or 16-bit.");
@@ -217,6 +216,7 @@ void FurnaceGUI::drawSampleEdit() {
         }
         ImGui::Combo("Filter",&resampleStrat,resampleStrats,6);
         if (ImGui::Button("Resample")) {
+          sample->prepareUndo(true);
           e->lockEngine([this,sample]() {
             if (!sample->resample(resampleTarget,resampleStrat)) {
               showError("couldn't resample! make sure your sample is 8 or 16-bit.");
@@ -253,6 +253,7 @@ void FurnaceGUI::drawSampleEdit() {
         ImGui::SameLine();
         ImGui::Text("(%.1fdB)",20.0*log10(amplifyVol/100.0f));
         if (ImGui::Button("Apply")) {
+          sample->prepareUndo(true);
           e->lockEngine([this,sample]() {
             SAMPLE_OP_BEGIN;
             float vol=amplifyVol/100.0f;
@@ -319,6 +320,7 @@ void FurnaceGUI::drawSampleEdit() {
         }
         if (ImGui::Button("Resize")) {
           int pos=(sampleSelStart==-1 || sampleSelStart==sampleSelEnd)?sample->samples:sampleSelStart;
+          sample->prepareUndo(true);
           e->lockEngine([this,sample,pos]() {
             if (!sample->insert(pos,silenceSize)) {
               showError("couldn't insert! make sure your sample is 8 or 16-bit.");
@@ -437,6 +439,7 @@ void FurnaceGUI::drawSampleEdit() {
         }
 
         if (ImGui::Button("Apply")) {
+          sample->prepareUndo(true);
           e->lockEngine([this,sample]() {
             SAMPLE_OP_BEGIN;
             float res=1.0-pow(sampleFilterRes,0.5f);
@@ -665,6 +668,7 @@ void FurnaceGUI::drawSampleEdit() {
               sampleDragActive=true;
               sampleSelStart=-1;
               sampleSelEnd=-1;
+              if (sampleDragMode) sample->prepareUndo(true);
               processDrags(ImGui::GetMousePos().x,ImGui::GetMousePos().y);
             }
           }
@@ -827,3 +831,27 @@ void FurnaceGUI::drawSampleEdit() {
   if (ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows)) curWindow=GUI_WINDOW_SAMPLE_EDIT;
   ImGui::End();
 }
+
+void FurnaceGUI::doUndoSample() {
+  if (!sampleEditOpen) return;
+  if (curSample<0 || curSample>=(int)e->song.sample.size()) return;
+  DivSample* sample=e->song.sample[curSample];
+  e->lockEngine([this,sample]() {
+    if (sample->undo()==2) {
+      e->renderSamples();
+      updateSampleTex=true;
+    }
+  });
+}
+
+void FurnaceGUI::doRedoSample() {
+  if (!sampleEditOpen) return;
+  if (curSample<0 || curSample>=(int)e->song.sample.size()) return;
+  DivSample* sample=e->song.sample[curSample];
+  e->lockEngine([this,sample]() {
+    if (sample->redo()==2) {
+      e->renderSamples();
+      updateSampleTex=true;
+    }
+  });
+}
\ No newline at end of file