diff --git a/src/render/software/CanvasPixelShader.cpp b/src/render/software/CanvasPixelShader.cpp
index f1362aa..ee8b9a9 100644
--- a/src/render/software/CanvasPixelShader.cpp
+++ b/src/render/software/CanvasPixelShader.cpp
@@ -12,7 +12,7 @@ CanvasPixelShader::CanvasPixelShader(const SoftwareCanvasRenderer &renderer, Can
 {
 }
 
-int CanvasPixelShader::processParallelUnit(int unit)
+void CanvasPixelShader::processParallelUnit(int unit)
 {
     // Locate the chunk we work on
     int prev_sub_chunk_size = chunk_size * 2;
@@ -33,7 +33,7 @@ int CanvasPixelShader::processParallelUnit(int unit)
         {
             if (interrupted)
             {
-                return 0;
+                return;
             }
 
             if (sub_chunk_size == chunk_size or x % prev_sub_chunk_size != 0 or y % prev_sub_chunk_size != 0)
@@ -60,6 +60,4 @@ int CanvasPixelShader::processParallelUnit(int unit)
             }
         }
     }
-
-    return 0;
 }
diff --git a/src/render/software/CanvasPixelShader.h b/src/render/software/CanvasPixelShader.h
index c5fe190..76a6c75 100644
--- a/src/render/software/CanvasPixelShader.h
+++ b/src/render/software/CanvasPixelShader.h
@@ -20,7 +20,7 @@ class CanvasPixelShader: public ParallelWorker
 public:
     CanvasPixelShader(const SoftwareCanvasRenderer &renderer, CanvasPortion *portion, int chunk_size, int sub_chunk_size, int chunks_x, int chunks_y);
 
-    virtual int processParallelUnit(int unit) override;
+    virtual void processParallelUnit(int unit) override;
 
 private:
     const SoftwareCanvasRenderer &renderer;
diff --git a/src/render/software/SkyRasterizer.cpp b/src/render/software/SkyRasterizer.cpp
index b8251c7..57866ae 100644
--- a/src/render/software/SkyRasterizer.cpp
+++ b/src/render/software/SkyRasterizer.cpp
@@ -34,7 +34,7 @@ void SkyRasterizer::rasterizeToCanvas(CanvasPortion* canvas)
 
     for (j = 0; j < res_j; j++)
     {
-        if (!renderer->addRenderProgress(0.0))
+        if (interrupted)
         {
             return;
         }
diff --git a/src/render/software/SoftwareCanvasRenderer.cpp b/src/render/software/SoftwareCanvasRenderer.cpp
index 9fdda8f..3d417a3 100644
--- a/src/render/software/SoftwareCanvasRenderer.cpp
+++ b/src/render/software/SoftwareCanvasRenderer.cpp
@@ -86,6 +86,10 @@ void SoftwareCanvasRenderer::interrupt()
     {
         current_work->interrupt();
     }
+    for (auto &rasterizer:getRasterizers())
+    {
+        rasterizer->interrupt();
+    }
 }
 
 const std::vector<Rasterizer *> &SoftwareCanvasRenderer::getRasterizers() const
diff --git a/src/render/software/TerrainRasterizer.cpp b/src/render/software/TerrainRasterizer.cpp
index 9bea440..815c7aa 100644
--- a/src/render/software/TerrainRasterizer.cpp
+++ b/src/render/software/TerrainRasterizer.cpp
@@ -152,25 +152,29 @@ void TerrainRasterizer::getTessellationInfo(CanvasPortion* canvas, int displaced
         for (i = 0; i < chunk_count - 1; i++)
         {
             _getChunk(renderer, &chunk, cx - radius_ext + chunk_size * i, cz - radius_ext, chunk_size, displaced);
-            if (!processChunk(canvas, &chunk, progress))
+            processChunk(canvas, &chunk, progress);
+            if (interrupted)
             {
                 return;
             }
 
             _getChunk(renderer, &chunk, cx + radius_int, cz - radius_ext + chunk_size * i, chunk_size, displaced);
-            if (!processChunk(canvas, &chunk, progress))
+            processChunk(canvas, &chunk, progress);
+            if (interrupted)
             {
                 return;
             }
 
             _getChunk(renderer, &chunk, cx + radius_int - chunk_size * i, cz + radius_int, chunk_size, displaced);
-            if (!processChunk(canvas, &chunk, progress))
+            processChunk(canvas, &chunk, progress);
+            if (interrupted)
             {
                 return;
             }
 
             _getChunk(renderer, &chunk, cx - radius_ext, cz + radius_int - chunk_size * i, chunk_size, displaced);
-            if (!processChunk(canvas, &chunk, progress))
+            processChunk(canvas, &chunk, progress);
+            if (interrupted)
             {
                 return;
             }
@@ -188,12 +192,11 @@ void TerrainRasterizer::getTessellationInfo(CanvasPortion* canvas, int displaced
     }
 }
 
-int TerrainRasterizer::processChunk(CanvasPortion* canvas, TerrainChunkInfo* chunk, double progress)
+void TerrainRasterizer::processChunk(CanvasPortion* canvas, TerrainChunkInfo* chunk, double progress)
 {
     tessellateChunk(canvas, chunk, chunk->detail_hint);
 
     renderer->render_progress = 0.05 * progress;
-    return !renderer->render_interrupt;
 }
 
 void TerrainRasterizer::rasterizeToCanvas(CanvasPortion *canvas)
diff --git a/src/render/software/TerrainRasterizer.h b/src/render/software/TerrainRasterizer.h
index b3abbfc..379c046 100644
--- a/src/render/software/TerrainRasterizer.h
+++ b/src/render/software/TerrainRasterizer.h
@@ -27,7 +27,7 @@ public:
     /**
      * Method called for each chunk tessellated by getTessellationInfo.
      */
-    int processChunk(CanvasPortion* canvas, TerrainChunkInfo* chunk, double progress);
+    void processChunk(CanvasPortion* canvas, TerrainChunkInfo* chunk, double progress);
 
     /**
      * Tessellate the terrain, calling processChunk for each chunk.
diff --git a/src/render/software/WaterRasterizer.cpp b/src/render/software/WaterRasterizer.cpp
index 428843b..16c82b1 100644
--- a/src/render/software/WaterRasterizer.cpp
+++ b/src/render/software/WaterRasterizer.cpp
@@ -55,7 +55,7 @@ void WaterRasterizer::rasterizeToCanvas(CanvasPortion *canvas)
 
     while (radius_int < 20000.0)
     {
-        if (!renderer->addRenderProgress(0.0))
+        if (interrupted)
         {
             return;
         }
diff --git a/src/system/ParallelWork.cpp b/src/system/ParallelWork.cpp
index 24a6096..fd6338a 100644
--- a/src/system/ParallelWork.cpp
+++ b/src/system/ParallelWork.cpp
@@ -18,9 +18,9 @@ public:
     {
     }
 
-    virtual int processParallelUnit(int unit)
+    virtual void processParallelUnit(int unit)
     {
-        return func(work, unit, data);
+        func(work, unit, data);
     }
 
 private:
diff --git a/src/system/ParallelWorker.h b/src/system/ParallelWorker.h
index 2b90518..1d6d8b4 100644
--- a/src/system/ParallelWorker.h
+++ b/src/system/ParallelWorker.h
@@ -20,7 +20,7 @@ public:
      *
      * This method will be called from any thread in the thread pool used by the ParallelWork.
      */
-    virtual int processParallelUnit(int unit) = 0;
+    virtual void processParallelUnit(int unit) = 0;
 
     /**
      * Method to reimplement to know when to interrupt the processing of units.