1 files changed, 5 insertions, 0 deletions

diff --git a/src/frame.c b/src/frame.c
index 94ec9fbdc7d..09c0e79bdef 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -1608,6 +1608,8 @@ next_frame (Lisp_Object frame, Lisp_Object minibuf)
   Lisp_Object f, tail;
   int passed = 0;
 
+  eassume (CONSP (Vframe_list));
+
   while (passed < 2)
     FOR_EACH_FRAME (tail, f)
       {
@@ -1630,6 +1632,8 @@ prev_frame (Lisp_Object frame, Lisp_Object minibuf)
 {
   Lisp_Object f, tail, prev = Qnil;
 
+  eassume (CONSP (Vframe_list));
+
   FOR_EACH_FRAME (tail, f)
     {
       if (EQ (frame, f) && !NILP (prev))
@@ -1915,6 +1919,7 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
   if (f == sf)
     {
       Lisp_Object tail;
+      eassume (CONSP (Vframe_list));
 
       /* Look for another visible frame on the same terminal.
          Do not call next_frame here because it may loop forever.