diff --git a/src/OT/Layout/GPOS/PairPosFormat2.hh b/src/OT/Layout/GPOS/PairPosFormat2.hh
index 1bb0d60ae..523e0e936 100644
--- a/src/OT/Layout/GPOS/PairPosFormat2.hh
+++ b/src/OT/Layout/GPOS/PairPosFormat2.hh
@@ -241,15 +241,16 @@ struct PairPosFormat2_4
     boring:
       buffer->unsafe_to_concat (buffer->idx, skippy_iter.idx + 1);
 
-
-    buffer->idx = skippy_iter.idx;
     if (len2)
     {
-      buffer->idx++;
+      skippy_iter.idx++;
       // https://github.com/harfbuzz/harfbuzz/issues/3824
-      buffer->unsafe_to_break (buffer->idx - 1, buffer->idx + 1);
+      // https://github.com/harfbuzz/harfbuzz/issues/3888#issuecomment-1326781116
+      buffer->unsafe_to_break (buffer->idx, skippy_iter.idx + 1);
     }
 
+    buffer->idx = skippy_iter.idx;
+
     return_trace (true);
   }
 
diff --git a/src/OT/Layout/GPOS/PairSet.hh b/src/OT/Layout/GPOS/PairSet.hh
index b1d9f83bc..2ad1f004c 100644
--- a/src/OT/Layout/GPOS/PairSet.hh
+++ b/src/OT/Layout/GPOS/PairSet.hh
@@ -132,8 +132,9 @@ struct PairSet
       if (len2)
       {
 	pos++;
-	// https://github.com/harfbuzz/harfbuzz/issues/3824
-	buffer->unsafe_to_break (pos - 1, pos + 1);
+      // https://github.com/harfbuzz/harfbuzz/issues/3824
+      // https://github.com/harfbuzz/harfbuzz/issues/3888#issuecomment-1326781116
+      buffer->unsafe_to_break (buffer->idx, pos + 1);
       }
 
       buffer->idx = pos;