diff --git a/src/buffer.c b/src/buffer.c
index 14eac92..93f9245 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -5777,7 +5777,7 @@
 bt_quickfix(buf_T *buf UNUSED)
 {
 #ifdef FEAT_QUICKFIX
-    return buf != NULL && buf->b_p_bt[0] == 'q';
+    return buf != NULL && buf_valid(buf) && buf->b_p_bt[0] == 'q';
 #else
     return FALSE;
 #endif
diff --git a/src/testdir/crash/bt_quickfix1_poc b/src/testdir/crash/bt_quickfix1_poc
new file mode 100644
index 0000000..97993fd
--- /dev/null
+++ b/src/testdir/crash/bt_quickfix1_poc
@@ -0,0 +1,5 @@
+au BufReadPre * exe 'sn' .. expand("<abuf>")
+call writefile([''],'X')
+sil! e X
+call writefile([''],'X')
+sil! e X
diff --git a/src/testdir/test_crash.vim b/src/testdir/test_crash.vim
index 27bf7b5..8deb797 100644
--- a/src/testdir/test_crash.vim
+++ b/src/testdir/test_crash.vim
@@ -49,6 +49,15 @@
 
   call TermWait(buf, 100)
 
+  let file = 'crash/bt_quickfix1_poc'
+  let args = printf(cmn_args, vim, file)
+  call term_sendkeys(buf, args ..
+    \ '  && echo "crash 6: [OK]" >> X_crash1_result.txt' .. "\<cr>")
+  " clean up
+  call delete('X')
+  " This test takes a bit longer
+  call TermWait(buf, 200)
+
   " clean up
   exe buf .. "bw!"
 
@@ -60,6 +69,7 @@
       \ 'crash 3: [OK]',
       \ 'crash 4: [OK]',
       \ 'crash 5: [OK]',
+      \ 'crash 6: [OK]',
       \ ]
 
   call assert_equal(expected, getline(1, '$'))
diff --git a/src/version.c b/src/version.c
index b604b57..f2ff8d6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -700,6 +700,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1859,
+/**/
     1858,
 /**/
     1857,