diff --git a/src/plugins/terminal/terminalwidget.cpp b/src/plugins/terminal/terminalwidget.cpp
index cb8e50166da..3ff38722c2c 100644
--- a/src/plugins/terminal/terminalwidget.cpp
+++ b/src/plugins/terminal/terminalwidget.cpp
@@ -1007,7 +1007,7 @@ void TerminalWidget::mousePressEvent(QMouseEvent *event)
             m_selection->start = m_surface->gridToPos(
                 {0, m_surface->posToGrid(m_selection->start).y()});
             m_selection->end = m_surface->gridToPos(
-                {viewport()->width(), m_surface->posToGrid(m_selection->end).y()});
+                {m_surface->liveSize().width(), m_surface->posToGrid(m_selection->end).y()});
         } else {
             m_selectLineMode = false;
             int pos = m_surface->gridToPos(globalToGrid(viewportToGlobal(event->pos())));
@@ -1037,8 +1037,14 @@ void TerminalWidget::mouseMoveEvent(QMouseEvent *event)
             std::swap(start, newEnd);
         }
 
-        m_selection->start = start;
-        m_selection->end = newEnd;
+        if (m_selectLineMode) {
+            m_selection->start = m_surface->gridToPos({0, m_surface->posToGrid(start).y()});
+            m_selection->end = m_surface->gridToPos(
+                {m_surface->liveSize().width(), m_surface->posToGrid(newEnd).y()});
+        } else {
+            m_selection->start = start;
+            m_selection->end = newEnd;
+        }
 
         if (old != *m_selection || selectionLog().isDebugEnabled())
             updateViewport();