diff --git a/emacs/notmuch-draft.el b/emacs/notmuch-draft.el
index ca720384..f928be87 100644
--- a/emacs/notmuch-draft.el
+++ b/emacs/notmuch-draft.el
@@ -135,7 +135,7 @@ Used when a new version is saved, or the message is sent."
     (let (secure-tag)
       (save-restriction
 	(message-narrow-to-headers)
-	(setq secure-tag (message-fetch-field "X-Notmuch-Emacs-Secure" 't))
+	(setq secure-tag (message-fetch-field "X-Notmuch-Emacs-Secure" t))
 	(message-remove-header "X-Notmuch-Emacs-Secure"))
       (message-goto-body)
       (when secure-tag
@@ -145,7 +145,7 @@ Used when a new version is saved, or the message is sent."
   "Returns t if there is an mml secure tag."
   (save-excursion
     (message-goto-body)
-    (re-search-forward notmuch-draft-encryption-tag-regex nil 't)))
+    (re-search-forward notmuch-draft-encryption-tag-regex nil t)))
 
 (defun notmuch-draft--query-encryption ()
   "Checks if we should save a message that should be encrypted.
@@ -207,7 +207,7 @@ applied to newly inserted messages)."
      (notmuch-draft-quote-some-mml)
      (notmuch-maildir-setup-message-for-saving)
      (notmuch-maildir-notmuch-insert-current-buffer
-      notmuch-draft-folder 't notmuch-draft-tags))
+      notmuch-draft-folder t notmuch-draft-tags))
     ;; We are now back in the original compose buffer. Note the
     ;; function notmuch-call-notmuch-process (called by
     ;; notmuch-maildir-notmuch-insert-current-buffer) signals an error
diff --git a/emacs/notmuch-maildir-fcc.el b/emacs/notmuch-maildir-fcc.el
index b1da93e6..32b8100e 100644
--- a/emacs/notmuch-maildir-fcc.el
+++ b/emacs/notmuch-maildir-fcc.el
@@ -76,7 +76,7 @@ directory if it does not exist yet when sending a mail."
   :require 'notmuch-fcc-initialization
   :group 'notmuch-send)
 
-(defcustom notmuch-maildir-use-notmuch-insert 't
+(defcustom notmuch-maildir-use-notmuch-insert t
   "Should fcc use notmuch insert instead of simple fcc."
   :type '(choice :tag "Fcc Method"
 		 (const :tag "Use notmuch insert" t)
@@ -246,8 +246,8 @@ If CREATE is non-nil then create the folder if necessary."
 \(r)etry, (c)reate folder, (i)gnore, or (e)dit the header? " '(?r ?c ?i ?e))))
 	 (cl-case response
 	   (?r (notmuch-maildir-fcc-with-notmuch-insert fcc-header))
-	   (?c (notmuch-maildir-fcc-with-notmuch-insert fcc-header 't))
-	   (?i 't)
+	   (?c (notmuch-maildir-fcc-with-notmuch-insert fcc-header t))
+	   (?i t)
 	   (?e (notmuch-maildir-fcc-with-notmuch-insert
 		(read-from-minibuffer "Fcc header: " fcc-header)))))))))
 
@@ -322,7 +322,7 @@ if successful, nil if not."
 It offers the user a chance to correct the header, or filesystem,
 if needed."
   (if (notmuch-maildir-fcc-dir-is-maildir-p fcc-header)
-      (notmuch-maildir-fcc-write-buffer-to-maildir fcc-header 't)
+      (notmuch-maildir-fcc-write-buffer-to-maildir fcc-header t)
     ;; The fcc-header is not a valid maildir see if the user wants to
     ;; fix it in some way.
     (let* ((prompt (format "Fcc %s is not a maildir: \
@@ -335,7 +335,7 @@ if needed."
 	      (message "No permission to create %s." fcc-header)
 	      (sit-for 2))
 	    (notmuch-maildir-fcc-file-fcc fcc-header))
-	(?i 't)
+	(?i t)
 	(?e (notmuch-maildir-fcc-file-fcc
 	     (read-from-minibuffer "Fcc header: " fcc-header)))))))
 
diff --git a/emacs/notmuch-mua.el b/emacs/notmuch-mua.el
index 29a2538b..c38cb5aa 100644
--- a/emacs/notmuch-mua.el
+++ b/emacs/notmuch-mua.el
@@ -539,11 +539,11 @@ tag, or the user confirms they mean it."
       (goto-char (point-max))
       (or
        ;; We are always fine if there is no secure tag.
-       (not (search-backward "<#secure" nil 't))
+       (not (search-backward "<#secure" nil t))
        ;; There is a secure tag, so it must be at the start of the
        ;; body, with no secure tag earlier (i.e., in the headers).
        (and (= (point) body-start)
-	    (not (search-backward "<#secure" nil 't)))
+	    (not (search-backward "<#secure" nil t)))
        ;; The user confirms they means it.
        (yes-or-no-p "\
 There is a <#secure> tag not at the start of the body. It is
@@ -583,7 +583,7 @@ unencrypted.  Really send? "))))
 
 (defun notmuch-mua-send-and-exit (&optional arg)
   (interactive "P")
-  (notmuch-mua-send-common arg 't))
+  (notmuch-mua-send-common arg t))
 
 (defun notmuch-mua-send (&optional arg)
   (interactive "P")
diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index c9b1e966..056c4e30 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -1751,7 +1751,7 @@ user decision and we should not override it."
 	  (funcall notmuch-show-mark-read-function (window-start) (window-end))
 	((debug error)
 	 (unless notmuch-show--seen-has-errored
-	   (setq notmuch-show--seen-has-errored 't)
+	   (setq notmuch-show--seen-has-errored t)
 	   (setq header-line-format
 		 (concat header-line-format
 			 (propertize
diff --git a/emacs/notmuch-tag.el b/emacs/notmuch-tag.el
index dc9a2186..925de78c 100644
--- a/emacs/notmuch-tag.el
+++ b/emacs/notmuch-tag.el
@@ -524,7 +524,7 @@ and vice versa."
 		      (symbol-value tag)
 		    tag))
 	     (tag-change (if reverse
-			     (notmuch-tag-change-list tag 't)
+			     (notmuch-tag-change-list tag t)
 			   tag))
 	     (name (or (and (not (string= name ""))
 			    name)