diff --git a/src/alloc.c b/src/alloc.c
index f372847ba55..791d5168a7a 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -953,6 +953,7 @@ DEFUN ("make-marker", Fmake_marker, Smake_marker, 0, 0, 0,
   p->buffer = 0;
   p->bufpos = 0;
   p->chain = Qnil;
+  p->insertion_type = 0;
   return val;
 }