diff --git a/src/Parsers/ExpressionElementParsers.cpp b/src/Parsers/ExpressionElementParsers.cpp
index 2434f7dbc42..3f4403bc264 100644
--- a/src/Parsers/ExpressionElementParsers.cpp
+++ b/src/Parsers/ExpressionElementParsers.cpp
@@ -585,7 +585,7 @@ static bool tryParseFrameDefinition(ASTWindowDefinition * node, IParser::Pos & p
 
         if (keyword_preceding.ignore(pos, expected))
         {
-            node->frame.begin_offset = - node->frame.begin_offset;
+            node->frame.begin_offset = -node->frame.begin_offset;
         }
         else if (keyword_following.ignore(pos, expected))
         {
diff --git a/src/Processors/Transforms/WindowTransform.cpp b/src/Processors/Transforms/WindowTransform.cpp
index 634c588beb0..775a9e23191 100644
--- a/src/Processors/Transforms/WindowTransform.cpp
+++ b/src/Processors/Transforms/WindowTransform.cpp
@@ -434,18 +434,15 @@ void WindowTransform::advanceFrameEndCurrentRow()
 
 //    fmt::print(stderr, "first row {} last {}\n", frame_end.row, rows_end);
 
-    // We could retreat the frame_end here, but for some reason I am reluctant
-    // to do this... It would have better data locality.
-    auto reference = current_row;
+    // Advance frame_end while it is still peers with the current row.
     for (; frame_end.row < rows_end; ++frame_end.row)
     {
-        if (!arePeers(reference, frame_end))
+        if (!arePeers(current_row, frame_end))
         {
 //            fmt::print(stderr, "{} and {} don't match\n", reference, frame_end);
             frame_ended = true;
             return;
         }
-        reference = frame_end;
     }
 
     // Might have gotten to the end of the current block, have to properly