diff --git a/Doc/changelog.docu b/Doc/changelog.docu
index 820466d7..8f07e75e 100644
--- a/Doc/changelog.docu
+++ b/Doc/changelog.docu
@@ -60,6 +60,12 @@
 <li>Obj writer: Fix OBJ material files and face color (Thanks to Sven-Kristofer Pilz for the patch) </li>
 </ul>
 
+<b>Tools</b>
+<ul>
+<li>Decimater: Added missing preprocess collapse call in size_t DecimaterT<Mesh>::decimate(size_t _n_collapses)  (Thanks to Andrej Ivanis for the hint)</li>
+</ul>
+
+
 
 <b>Build System</b>
 <ul>
diff --git a/src/OpenMesh/Tools/Decimater/DecimaterT.cc b/src/OpenMesh/Tools/Decimater/DecimaterT.cc
index f8e3d9f8..31c47103 100644
--- a/src/OpenMesh/Tools/Decimater/DecimaterT.cc
+++ b/src/OpenMesh/Tools/Decimater/DecimaterT.cc
@@ -215,6 +215,9 @@ size_t DecimaterT<Mesh>::decimate(size_t _n_collapses) {
     for (; vv_it.is_valid(); ++vv_it)
       support.push_back(*vv_it);
 
+    // pre-processing
+    this->preprocess_collapse(ci);
+
     // perform collapse
     mesh_.collapse(v0v1);
     ++n_collapses;