diff --git a/src/ops.c b/src/ops.c
index e9cfb1d..e35b033 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -629,26 +629,9 @@ block_insert(
 
 #ifdef FEAT_MBYTE
 	if (has_mbyte && spaces > 0)
-	{
-	    int off;
+	    // avoid copying part of a multi-byte character
+	    offset -= (*mb_head_off)(oldp, oldp + offset);
 
-	    /* Avoid starting halfway a multi-byte character. */
-	    if (b_insert)
-	    {
-		off = (*mb_head_off)(oldp, oldp + offset + spaces);
-		spaces -= off;
-		count -= off;
-	    }
-	    else
-	    {
-		// spaces fill the gap, the character that's at the edge moves
-		// right
-		off = (*mb_head_off)(oldp, oldp + offset);
-		offset -= off;
-	    }
-	    spaces -= off;
-	    count -= off;
-	}
 #endif
 
 	// Make sure the allocated size matches what is actually copied below.
diff --git a/src/testdir/test_utf8.vim b/src/testdir/test_utf8.vim
index 24e3db8..1042720 100644
--- a/src/testdir/test_utf8.vim
+++ b/src/testdir/test_utf8.vim
@@ -9,7 +9,7 @@ func Test_visual_block_insert()
   new
   call setline(1, ["aaa", "あああ", "bbb"])
   exe ":norm! gg0l\<C-V>jjIx\<Esc>"
-  call assert_equal(['axaa', 'xあああ', 'bxbb'], getline(1, '$'))
+  call assert_equal(['axaa', ' xあああ', 'bxbb'], getline(1, '$'))
   bwipeout!
 endfunc