diff --git a/pudb/debugger.py b/pudb/debugger.py
index ff111925..0f0cfe98 100644
--- a/pudb/debugger.py
+++ b/pudb/debugger.py
@@ -313,6 +313,7 @@ def setup_state(self):
     def restart(self):
         from linecache import checkcache
         checkcache()
+        self.ui.reset_global_watch_values()
         self.ui.set_source_code_provider(NullSourceCodeProvider())
         self.setup_state()
 
diff --git a/pudb/var_view.py b/pudb/var_view.py
index 344f9e79..01532d71 100644
--- a/pudb/var_view.py
+++ b/pudb/var_view.py
@@ -247,6 +247,9 @@ def set_method(self, method):
     def set_scope(self, scope):
         self.scope = scope
 
+    def reset_value(self):
+        self._value = self.NOT_EVALUATED
+
 
 class WatchEvalError:
     def __str__(self):
@@ -840,6 +843,10 @@ def change_watch_scope(self, watch_expr, fvi=None):
         self.delete_watch(watch_expr, fvi)
         self.add_watch(watch_expr, fvi)
 
+    def reset_global_watch_values(self):
+        for watch_expr in self.global_watches:
+            watch_expr.reset_value()
+
 # }}}
 
 # vim: foldmethod=marker