diff --git a/imageviewer-qt4.cpp b/imageviewer-qt4.cpp
index 09d480a..afe63ba 100644
--- a/imageviewer-qt4.cpp
+++ b/imageviewer-qt4.cpp
@@ -396,7 +396,7 @@ void ImageViewer::succeedingHistogrammAdaption() {
     for(int i=0; i<256; i++) histogramm_map[i] = -1;
     int source_cursor = 0;
     double used_space = 0.0;
-    double* source_histogramm = working_copy->getRelativeIntensityHistogramm();
+    double* source_histogramm = original->getRelativeIntensityHistogramm();
     double* target_cummulative_histogramm = histogramm_reference->getRelativeCumulativeIntensityHistogramm();
     for(int i=0; i<256; i++) {
       double free_total_space = target_cummulative_histogramm[i];