diff --git a/libs/patch/PatchIterators.h b/libs/patch/PatchIterators.h
index 0537f5fd0e..d39a8ae5a3 100644
--- a/libs/patch/PatchIterators.h
+++ b/libs/patch/PatchIterators.h
@@ -206,11 +206,12 @@ class ColumnWisePatchIteratorBase :
 
     ColumnWisePatchIteratorBase(IPatch& patch, std::size_t startColumn, std::size_t endColumn, int rowDelta) :
         PatchControlIterator(patch, rowDelta > 0 ? 0 : patch.getHeight() - 1, startColumn, 
-            std::bind(ColumnWisePatchIteratorBase::moveNext, std::placeholders::_1, std::ref(patch), endColumn, rowDelta))
+            std::bind(ColumnWisePatchIteratorBase::moveNext, std::placeholders::_1, std::ref(patch), 
+                endColumn, startColumn <= endColumn ? +1 : -1, rowDelta))
     {}
 
 private:
-    static void moveNext(PatchControlIterator& it, const IPatch& patch, std::size_t endColumn, int rowDelta)
+    static void moveNext(PatchControlIterator& it, const IPatch& patch, std::size_t endColumn, int columnDelta, int rowDelta)
     {
         auto nextRow = it.getRow() + rowDelta;
         auto nextColumn = it.getColumn();
@@ -220,7 +221,10 @@ class ColumnWisePatchIteratorBase :
         {
             // Advance to the next column
             // If that doesn't succeed, just leave the indices out of bounds
-            if (++nextColumn <= endColumn)
+            nextColumn += columnDelta;
+
+            if (columnDelta > 0 && nextColumn <= endColumn ||
+                columnDelta < 0 && nextColumn >= endColumn)
             {
                 nextRow = rowDelta > 0 ? 0 : patch.getHeight() - 1;
             }
@@ -273,11 +277,12 @@ class RowWisePatchIteratorBase :
 
     RowWisePatchIteratorBase(IPatch& patch, std::size_t startRow, std::size_t endRow, int columnDelta) :
         PatchControlIterator(patch, startRow, columnDelta > 0 ? 0 : patch.getWidth() - 1,
-            std::bind(RowWisePatchIteratorBase::moveNext, std::placeholders::_1, std::ref(patch), endRow, columnDelta))
+            std::bind(RowWisePatchIteratorBase::moveNext, std::placeholders::_1, std::ref(patch), 
+                endRow, startRow <= endRow ? +1 : -1, columnDelta))
     {}
 
 private:
-    static void moveNext(PatchControlIterator& it, const IPatch& patch, std::size_t endRow, int columnDelta)
+    static void moveNext(PatchControlIterator& it, const IPatch& patch, std::size_t endRow, int rowDelta, int columnDelta)
     {
         auto nextColumn = it.getColumn() + columnDelta;
         auto nextRow = it.getRow();
@@ -287,7 +292,10 @@ class RowWisePatchIteratorBase :
         {
             // Advance to the next row
             // If that doesn't succeed, just leave the indices out of bounds
-            if (++nextRow <= endRow)
+            nextRow += rowDelta;
+
+            if (rowDelta > 0 && nextRow <= endRow ||
+                rowDelta < 0 && nextRow >= endRow)
             {
                 nextColumn = columnDelta > 0 ? 0 : patch.getWidth() - 1;
             }
diff --git a/test/PatchIterators.cpp b/test/PatchIterators.cpp
index 6589cd274b..45723a6e17 100644
--- a/test/PatchIterators.cpp
+++ b/test/PatchIterators.cpp
@@ -147,12 +147,14 @@ TEST_F(PatchIteratorTest, IterateOverWholePatchRowWiseColumnBackwards)
     EXPECT_EQ(expected, expectedValues.end()); // assume no underflow
 }
 
-void iterateOverPartialPatchColumnWise(IPatch& patch, std::size_t startCol, std::size_t endCol, bool rowBackwards)
+void iterateOverPartialPatchColumnWise(IPatch& patch, int startCol, int endCol, bool rowBackwards)
 {
     std::vector<Vector3> expectedValues;
 
     // Fill the vector with the expected values
-    for (auto col = startCol; col <= endCol; ++col)
+    int step = startCol <= endCol ? +1 : -1;
+
+    for (auto col = startCol; col != endCol + step; col += step)
     {
         if (rowBackwards)
         {
@@ -197,6 +199,15 @@ TEST_F(PatchIteratorTest, IterateOverPartialPatchColumnWise)
     iterateOverPartialPatchColumnWise(patch->getPatch(), 1, 3, false);
     iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 4, false);
     iterateOverPartialPatchColumnWise(patch->getPatch(), 3, 4, false);
+
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 0, false);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 3, 0, false);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 0, 0, false);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 0, false);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 3, false);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 3, 1, false);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 4, false);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 3, false);
 }
 
 TEST_F(PatchIteratorTest, IterateOverPartialPatchColumnWiseRowBackwards)
@@ -212,14 +223,25 @@ TEST_F(PatchIteratorTest, IterateOverPartialPatchColumnWiseRowBackwards)
     iterateOverPartialPatchColumnWise(patch->getPatch(), 1, 3, true);
     iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 4, true);
     iterateOverPartialPatchColumnWise(patch->getPatch(), 3, 4, true);
+
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 0, true);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 3, 0, true);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 0, 0, true);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 0, true);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 3, true);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 3, 1, true);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 4, true);
+    iterateOverPartialPatchColumnWise(patch->getPatch(), 4, 3, true);
 }
 
-void iterateOverPartialPatchRowWise(IPatch& patch, std::size_t startRow, std::size_t endRow, bool columnBackwards)
+void iterateOverPartialPatchRowWise(IPatch& patch, int startRow, int endRow, bool columnBackwards)
 {
     std::vector<Vector3> expectedValues;
 
     // Fill the vector with the expected values
-    for (auto row = startRow; row <= endRow; ++row)
+    int step = startRow <= endRow ? +1 : -1;
+
+    for (auto row = startRow; row != endRow + step; row += step)
     {
         if (columnBackwards)
         {
@@ -264,6 +286,15 @@ TEST_F(PatchIteratorTest, IterateOverPartialPatchRowWise)
     iterateOverPartialPatchRowWise(patch->getPatch(), 1, 3, false);
     iterateOverPartialPatchRowWise(patch->getPatch(), 6, 6, false);
     iterateOverPartialPatchRowWise(patch->getPatch(), 3, 4, false);
+
+    iterateOverPartialPatchRowWise(patch->getPatch(), 6, 0, false);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 3, 0, false);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 0, 0, false);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 4, 0, false);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 6, 3, false);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 3, 1, false);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 6, 6, false);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 4, 3, false);
 }
 
 TEST_F(PatchIteratorTest, IterateOverPartialPatchRowWiseColumnBackwards)
@@ -279,6 +310,15 @@ TEST_F(PatchIteratorTest, IterateOverPartialPatchRowWiseColumnBackwards)
     iterateOverPartialPatchRowWise(patch->getPatch(), 1, 3, true);
     iterateOverPartialPatchRowWise(patch->getPatch(), 6, 6, true);
     iterateOverPartialPatchRowWise(patch->getPatch(), 3, 4, true);
+
+    iterateOverPartialPatchRowWise(patch->getPatch(), 6, 0, true);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 3, 0, true);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 0, 0, true);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 4, 0, true);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 6, 3, true);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 3, 1, true);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 6, 6, true);
+    iterateOverPartialPatchRowWise(patch->getPatch(), 4, 3, true);
 }
 
 void iterateOverSingleColum(IPatch& patch, std::size_t colToTest)