diff --git a/test/lisp/textmodes/ispell-resources/fake-aspell-new.bash b/test/lisp/textmodes/ispell-resources/fake-aspell-new.bash
index 0cc7ede8e38..5aa267a5888 100755
--- a/test/lisp/textmodes/ispell-resources/fake-aspell-new.bash
+++ b/test/lisp/textmodes/ispell-resources/fake-aspell-new.bash
@@ -17,6 +17,9 @@ if [[ "$HOME" == '' ]] ; then
     exit 3
 fi
 
+dictionary=UNSET
+repl=UNSET
+
 show_vv()
 {
     printf  '%s\n' "@(#) International Ispell Version 3.1.20 (but really Aspell 0.60.0)"
@@ -94,11 +97,24 @@ while :; do
             exit
             ;;
         -a)       # imitate REPL
-	    imitate_pipe
-	    exit
+	    repl=pipe
             ;;
+	-d)
+	    if [ "$2" ]; then
+                dictionary=$2
+		if [[ "$dictionary" == "2110001888290146229" ]] ; then exit 3 ; fi
+                shift
+            else
+                printf 'ERROR: "-d" requires an argument.' 1>&2
+		exit 1
+            fi
+	    ;;
+	-d*)
+	    dictionary=${1#-d}
+	    if [[ "$dictionary" == "2110001888290146229" ]] ; then exit 3 ; fi
+	    ;;
 	-?*)
-            printf 'WARN: Unknown option (ignored): %s\n' "$1" >&2
+	    :
 	    ;;
         *)
             break
@@ -106,6 +122,11 @@ while :; do
     shift
 done
 
-printf 'Usage: aspell [options] <command>\n'
+if [[ "$repl" == "pipe" ]] ; then
+    imitate_pipe
+else
+    printf 'Usage: aspell [options] <command>\n'
+    exit 4
+fi
 
 #printf 'this place should be unreachable\n' >> /tmp/lwf_mock-aspell.log
diff --git a/test/lisp/textmodes/ispell-tests/ispell-tests-common.el b/test/lisp/textmodes/ispell-tests/ispell-tests-common.el
index 30a4336f094..4bf3a79b769 100644
--- a/test/lisp/textmodes/ispell-tests/ispell-tests-common.el
+++ b/test/lisp/textmodes/ispell-tests/ispell-tests-common.el
@@ -37,15 +37,14 @@
   "Path to the mock backend.")
 
 
-(let* ((backend-binaries (list "ispell" "aspell"  "hunspell"  "enchant-2" fake-aspell-path)
-                         )
+(let* ((backend-binaries (list "ispell" "aspell"  "hunspell"  "enchant-2" fake-aspell-path))
        (filter-binaries (seq-filter
                          (lambda (b)
                            (and
                             (executable-find b)
                             (equal 0
                                    (with-temp-buffer
-                                     (call-process b nil t "-a")))))
+                                     (call-process b nil t nil "-a")))))
                          backend-binaries)))
 
   (defun ispell-tests--some-backend-available-p ()
@@ -86,7 +85,8 @@
            (forward-line 1)
            (let* ((s (buffer-substring (point) (line-end-position))))
              (file-name-sans-extension
-              (file-name-nondirectory s)))))))
+              (file-name-nondirectory s)))))
+        (t "english")))
 
 (eval-when-compile
   (require 'cl-macs))
@@ -140,6 +140,7 @@ its best."
 (defconst ispell-tests--constants/russian/correct "привет")
 (defconst ispell-tests--constants/russian/wrong "ыфаывфафыввпфыв")
 (defconst ispell-tests--constants/completion "waveguides")
+(defconst ispell-tests--constants/nonexistent-dictionary "2110001888290146229")
 
 (provide 'ispell-tests-common)
 
diff --git a/test/lisp/textmodes/ispell-tests/ispell-tests.el b/test/lisp/textmodes/ispell-tests/ispell-tests.el
index 605b634e9a8..b43d32ae95d 100644
--- a/test/lisp/textmodes/ispell-tests/ispell-tests.el
+++ b/test/lisp/textmodes/ispell-tests/ispell-tests.el
@@ -836,14 +836,14 @@ hunspell.  Hence skipping."
 
 (ert-deftest ispell/ispell-accept-buffer-local-defs/received-file ()
   "Check that `ispell-accept-buffer-local-defs' is broken when a file has a nonexistent file-local dictionary.
-We do not control this data, but this should make ispell.el failx."
+We do not control this data, but this should make ispell.el fail."
   :expected-result :failed
   (with-environment-variables (("HOME" temporary-file-directory))
     (with-temp-buffer
       (ispell-tests--letopt
           ((ispell-program-name (ispell-tests--some-backend)))
 
-        (let ((test-dictname (format "%s" (random))))
+        (let ((test-dictname ispell-tests--constants/nonexistent-dictionary))
           (insert
            (car ispell-tests--constants/english/correct-list) "\n\n\n"
            ispell-dictionary-keyword test-dictname "\n")