diff --git a/src/modification.cc b/src/modification.cc
index 2539ea3a..876463f1 100644
--- a/src/modification.cc
+++ b/src/modification.cc
@@ -165,6 +165,12 @@ std::vector<Modification> compute_modifications(memoryview<Buffer::Change> chang
             }
             ByteCoord num_removed_from_added = std::min(num_removed, num_added_after_pos);
             modif.num_added -= num_removed_from_added;
+
+            if (change.begin.line == modif.new_coord.line)
+                modif.num_added.column += change.begin.column - modif.new_coord.column;
+            else
+                modif.num_added.column += change.begin.column;
+
             modif.num_removed += num_removed - num_removed_from_added;
 
             for (auto it = next; it != res.end(); ++it)
diff --git a/src/unit_tests.cc b/src/unit_tests.cc
index 6bae7a80..36c885bd 100644
--- a/src/unit_tests.cc
+++ b/src/unit_tests.cc
@@ -204,6 +204,19 @@ void test_modification()
         kak_assert(modif.num_added == ByteCoord{0 COMMA 0});
         kak_assert(modif.num_removed == ByteCoord{1 COMMA 0});
     }
+    {
+        std::vector<Buffer::Change> change = {
+            { Buffer::Change::Insert, {1, 10}, {2, 0}, false },
+            { Buffer::Change::Erase, {1, 20}, {2, 10}, false },
+        };
+        auto modifs = compute_modifications(change);
+        kak_assert(modifs.size() == 1);
+        auto& modif = modifs[0];
+        kak_assert(modif.old_coord == ByteCoord{1 COMMA 10});
+        kak_assert(modif.new_coord == ByteCoord{1 COMMA 10});
+        kak_assert(modif.num_added == ByteCoord{0 COMMA 10});
+        kak_assert(modif.num_removed == ByteCoord{0 COMMA 10});
+    }
 
     Buffer buffer("test", Buffer::Flags::None,
                   { "tchou mutch\n",