diff --git a/src/intervals.c b/src/intervals.c
index a66594ceea2..585ef18bd2e 100644
--- a/src/intervals.c
+++ b/src/intervals.c
@@ -1187,7 +1187,7 @@ delete_interval (register INTERVAL i)
   register INTERVAL parent;
   ptrdiff_t amt = LENGTH (i);
 
-  eassert (amt == 0);		/* Only used on zero-length intervals now.  */
+  eassert (amt <= 0);	/* Only used on zero total-length intervals now.  */
 
   if (ROOT_INTERVAL_P (i))
     {