diff --git a/ci/coq-tests.el b/ci/coq-tests.el
index 8040b1229..f06e13243 100644
--- a/ci/coq-tests.el
+++ b/ci/coq-tests.el
@@ -112,11 +112,9 @@
 
 (defun coq-set-flags (val flags)
   (when (member 'show-proof-stepwise flags) (setq coq-show-proof-stepwise val))
-  (when (member 'diffs-on flags) (if val (setq coq-diffs 'on) (setq coq-diffs 'off)))
-  )
+  (when (member 'diffs-on flags) (if val (setq coq-diffs 'on) (setq coq-diffs 'off))))
 
-
-(defun coq-fixture-on-file (file  body &rest flags)
+(defun coq-fixture-on-file (file body &rest flags)
   "Fixture to setup the test env: open FILE if non-nil, or a temp file
 then evaluate the BODY function and finally tear-down (exit Coq)."
 ;; AVOID THE FOLLOWING ERROR:
@@ -167,24 +165,28 @@ For example, COMMENT could be (*test-definition*)"
   (goto-char (point-min))
   (search-forward comment))
 
-(defun coq-should-response (message)
-  (should (equal message
+(defun coq-should-response (str)
+  (should (equal str
 		 (string-trim
                   (with-current-buffer "*response*"
                     (buffer-substring-no-properties (point-min) (point-max)))))))
 
-(defun coq-should-buffer (message)
-  (should (string-match-p message
+(defun coq-should-buffer-regexp (regexp)
+  (should (string-match-p regexp
 		 (string-trim
                   (with-current-buffer "*coq*"
                     (buffer-substring-no-properties (point-min) (point-max)))))))
 
+(defun coq-should-buffer-string (str)
+  "Particular case of `coq-should-buffer-regexp'."
+  (coq-should-buffer-regexp (regexp-quote str)))
+
 ;; TODO: Use https://github.com/rejeep/ert-async.el
 ;; and/or ERT https://www.gnu.org/software/emacs/manual/html_node/ert/index.html
 
 (ert-deftest 010_coq-test-running ()
   "Test that the coqtop process is started properly."
-  (coq-fixture-on-file nil 
+  (coq-fixture-on-file nil
    (lambda ()
      (coq-test-cmd "Print 0.")
      ;; (should (process-list)) ; wouldn't be a strong enough assert.
@@ -193,8 +195,8 @@ For example, COMMENT could be (*test-definition*)"
 
 (ert-deftest 020_coq-test-definition ()
   "Test *response* output after asserting a Definition."
-  (coq-fixture-on-file 
-   (coq-test-full-path "test_stepwise.v") 
+  (coq-fixture-on-file
+   (coq-test-full-path "test_stepwise.v")
    (lambda ()
      (coq-test-goto-before "(*test-definition*)")
      (proof-goto-point)
@@ -203,9 +205,9 @@ For example, COMMENT could be (*test-definition*)"
 
 
 (ert-deftest 021_coq-test-regression-goto-point ()
-  "Regression test for proof-goto-point after a comment, PR #90"
-  (coq-fixture-on-file 
-   (coq-test-full-path "test_stepwise.v") 
+  "Regression test for proof-goto-point after a comment, PR #490"
+  (coq-fixture-on-file
+   (coq-test-full-path "test_stepwise.v")
    (lambda ()
        (coq-test-goto-after "(*test-definition*)")
        (proof-goto-point)
@@ -215,8 +217,8 @@ For example, COMMENT could be (*test-definition*)"
 
 (ert-deftest 030_coq-test-position ()
   "Test locked region after Qed."
-  (coq-fixture-on-file 
-   (coq-test-full-path "test_stepwise.v") 
+  (coq-fixture-on-file
+   (coq-test-full-path "test_stepwise.v")
    (lambda ()
      (coq-test-goto-before " (*test-lemma*)")
      (let ((proof-point (point)))
@@ -227,8 +229,8 @@ For example, COMMENT could be (*test-definition*)"
 
 (ert-deftest 040_coq-test-insert ()
   "Test retract on insert from Qed."
-  (coq-fixture-on-file 
-   (coq-test-full-path "test_stepwise.v") 
+  (coq-fixture-on-file
+   (coq-test-full-path "test_stepwise.v")
    (lambda ()
      (coq-test-goto-before " (*test-lemma*)")
      (proof-goto-point)
@@ -243,8 +245,8 @@ For example, COMMENT could be (*test-definition*)"
 
 (ert-deftest 050_coq-test-lemma-false ()
   "Test retract on proof error."
-  (coq-fixture-on-file 
-   (coq-test-full-path "test_stepwise.v") 
+  (coq-fixture-on-file
+   (coq-test-full-path "test_stepwise.v")
    (lambda ()
      (coq-test-goto-before " (*test-lemma2*)")
      (let ((proof-point (save-excursion (coq-test-goto-after "(*error*)")))) 
@@ -269,8 +271,8 @@ For example, COMMENT could be (*test-definition*)"
 
 (ert-deftest 070_coq-test-regression-wholefile-no-proof ()
   "Regression test for no proof bug"
-  (coq-fixture-on-file 
-   (coq-test-full-path "test_wholefile.v") 
+  (coq-fixture-on-file
+   (coq-test-full-path "test_wholefile.v")
    (lambda ()
      (proof-process-buffer)
      (proof-shell-wait)
@@ -280,28 +282,28 @@ For example, COMMENT could be (*test-definition*)"
 
 (ert-deftest 080_coq-test-regression-show-proof-stepwise()
   "Regression test for the \"Show Proof\" option"
-    (coq-fixture-on-file 
-   (coq-test-full-path "test_stepwise.v") 
+    (coq-fixture-on-file
+   (coq-test-full-path "test_stepwise.v")
    (lambda ()
      (coq-test-goto-before " (*test-insert*)")
      (proof-goto-point)
      (proof-shell-wait)
-     (coq-should-response "(fun (A : Prop) (proof_of_A : A) => ?Goal)"))
+     (coq-should-buffer-string "(fun (A : Prop) (proof_of_A : A) => ?Goal)"))
    'show-proof-stepwise))
 
 
 (ert-deftest 081_coq-test-regression-show-proof-diffs()
   "Test for Show Proof Diffs"
-    (coq-fixture-on-file 
-   (coq-test-full-path "test_stepwise.v") 
+    (coq-fixture-on-file
+   (coq-test-full-path "test_stepwise.v")
    (lambda ()
      (coq-test-goto-before " (*test-insert*)")
      (proof-goto-point)
      (proof-shell-wait)
      ;; If coq--post-v811, it should be "Show Proof Diffs." otherwise "Show Proof."
      (if (coq--post-v811)
-	 (coq-should-buffer  "<diff\\.added\\.bg>(fun <diff\\.added>(</diff\\.added>A : Prop<diff\\.added>) (proof_of_A : A)</diff\\.added> => \\?Goal)</diff\\.added\\.bg>")
-       (coq-should-buffer "(fun (A : Prop) (proof_of_A : A) => \\?Goal)")))
+	 (coq-should-buffer-string  "<diff.added.bg>(fun <diff.added>(</diff.added>A : Prop<diff.added>) (proof_of_A : A)</diff.added> => ?Goal)</diff.added.bg>")
+       (coq-should-buffer-string "(fun (A : Prop) (proof_of_A : A) => ?Goal)")))
    'show-proof-stepwise 'diffs-on))
  
 
diff --git a/coq/coq.el b/coq/coq.el
index df7c5a668..efa603499 100644
--- a/coq/coq.el
+++ b/coq/coq.el
@@ -1237,13 +1237,6 @@ should match the `coq-show-proof-diffs-regexp'."
      ;; the number of nested goals, then Unset Silent and Show the goal
      (and (string-match-p "BackTo\\s-" cmd)
           (> (length coq-last-but-one-proofstack) coq--retract-naborts)))
-    ;; "Set Diffs" always re-prints the proof context with (if enabled) diffs
-    ;; (list "Unset Silent." (if (coq--post-v810) (coq-diffs) "Show.")
-    ;;       (when coq-show-proof-stepwise
-    ;;         (or
-    ;;          (when (eq coq-diffs 'off) "Show Proof.")
-    ;;          (when (eq coq-diffs 'on) "Show Proof Diffs.")
-    ;;          (when (eq coq-diffs 'removed) "Show Proof Diffs removed.")))))
     (let ((showlist (list "Unset Silent." (if (coq--post-v810) (coq-diffs) "Show."))))
       (when coq-show-proof-stepwise
         (add-to-list 'showlist