diff --git a/src/textprop.c b/src/textprop.c
index ce6b66c..526a6f0 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -915,11 +915,47 @@
 /*
  * Adjust the columns of text properties in line "lnum" after position "col" to
  * shift by "bytes_added" (can be negative).
+ * Note that "col" is zero-based, while tp_col is one-based.
+ * Only for the current buffer.
+ * Called is expected to check b_has_textprop and "bytes_added" being non-zero.
  */
     void
-adjust_prop_columns(linenr_T lnum UNUSED, colnr_T col UNUSED, int bytes_added UNUSED)
+adjust_prop_columns(linenr_T lnum, colnr_T col, int bytes_added)
 {
-    // TODO
+    int		proplen;
+    char_u	*props;
+    textprop_T	tmp_prop;
+    proptype_T  *pt;
+    int		dirty = FALSE;
+    int		i;
+
+    proplen = get_text_props(curbuf, lnum, &props, TRUE);
+    if (proplen == 0)
+	return;
+
+    for (i = 0; i < proplen; ++i)
+    {
+	mch_memmove(&tmp_prop, props + i * sizeof(textprop_T),
+							   sizeof(textprop_T));
+	pt = text_prop_type_by_id(curbuf, tmp_prop.tp_type);
+
+	if (tmp_prop.tp_col >= col + (pt != NULL && (pt->pt_flags & PT_FLAG_INS_START_INCL) ? 2 : 1))
+	{
+	    tmp_prop.tp_col += bytes_added;
+	    dirty = TRUE;
+	}
+	else if (tmp_prop.tp_col + tmp_prop.tp_len > col + (pt != NULL && (pt->pt_flags & PT_FLAG_INS_END_INCL) ? 0 : 1))
+	{
+	    tmp_prop.tp_len += bytes_added;
+	    dirty = TRUE;
+	}
+	if (dirty)
+	{
+	    curbuf->b_ml.ml_flags |= ML_LINE_DIRTY;
+	    mch_memmove(props + i * sizeof(textprop_T), &tmp_prop,
+							   sizeof(textprop_T));
+	}
+    }
 }
 
 #endif // FEAT_TEXT_PROP