diff --git a/README.in.rst b/README.in.rst
index b23814c..aba80c4 100644
--- a/README.in.rst
+++ b/README.in.rst
@@ -61,7 +61,7 @@ How do I...
 ... report a bug?
    File an issue using ``M-x ein:dev-bug-report-template``.
 
-   First try ``emacs -Q -f package-initialize`` and reproduce the bug.  The ``-Q`` skips any user configuration that might interfere with EIN.
+   First try ``emacs -Q -f package-initialize --eval "(setq debug-on-error t)"`` and reproduce the bug.  The ``-Q`` skips any user configuration that might interfere with EIN.
 
    Note EIN is tested only for *released* GNU Emacs versions
    .. CI VERSION (see Makefile)
diff --git a/README.rst b/README.rst
index 4e4a770..4638c24 100644
--- a/README.rst
+++ b/README.rst
@@ -70,7 +70,7 @@ How do I...
 ... report a bug?
    File an issue using ``M-x ein:dev-bug-report-template``.
 
-   First try ``emacs -Q -f package-initialize`` and reproduce the bug.  The ``-Q`` skips any user configuration that might interfere with EIN.
+   First try ``emacs -Q -f package-initialize --eval "(setq debug-on-error t)"`` and reproduce the bug.  The ``-Q`` skips any user configuration that might interfere with EIN.
 
    Note EIN is tested only for *released* GNU Emacs versions
    25.1
diff --git a/lisp/ein-worksheet.el b/lisp/ein-worksheet.el
index 04217d5..3c081b0 100644
--- a/lisp/ein-worksheet.el
+++ b/lisp/ein-worksheet.el
@@ -1102,13 +1102,13 @@ If :above or :below specified, execute above/below the current cell."
                                            (lambda (my other)
                                              (not (string= (slot-value other 'cell-id) my)))
                                            current-id)))
-                 (append (when (and current-id above)
+                 (append (when above
                            (aif (seq-take-while not-matching all)
                                it
                              (prog1 nil
                                (ein:log 'info
                                  "ein:worksheet-execute-all-cells: no cells above current"))))
-                         (when (and current-id below)
+                         (when below
                            (seq-drop-while not-matching all))))
              all)))))
 
diff --git a/lisp/poly-ein.el b/lisp/poly-ein.el
index 6fba87c..b76fff5 100644
--- a/lisp/poly-ein.el
+++ b/lisp/poly-ein.el
@@ -6,7 +6,7 @@
 
 (defmacro poly-ein--remove-hook (label functions)
   "Remove any hooks saying LABEL from FUNCTIONS"
-  `(mapc (lambda (x) (when (cl-search ,label (symbol-name x))
+  `(mapc (lambda (x) (when (and (symbolp x) (cl-search ,label (symbol-name x)))
                        (remove-hook (quote ,functions) x t)))
          ,functions))