diff --git a/lisp/oc-basic.el b/lisp/oc-basic.el
index bf0153d1d..98242f3b8 100644
--- a/lisp/oc-basic.el
+++ b/lisp/oc-basic.el
@@ -89,42 +89,42 @@
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'symbol
-  :safe t)
+  :safe #'symbolp)
 
 (defcustom org-cite-basic-author-year-separator ", "
   "String used to separate cites in an author-year configuration."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'string
-  :safe t)
+  :safe #'stringp)
 
 (defcustom org-cite-basic-max-key-distance 2
   "Maximum (Levenshtein) distance between a wrong key and its suggestions."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'integer
-  :safe t)
+  :safe #'integerp)
 
 (defcustom org-cite-basic-author-column-end 25
   "Column where author field ends in completion table, as an integer."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'integer
-  :safe t)
+  :safe #'integerp)
 
 (defcustom org-cite-basic-column-separator "  "
   "Column separator in completion table, as a string."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'string
-  :safe t)
+  :safe #'stringp)
 
 (defcustom org-cite-basic-mouse-over-key-face 'highlight
   "Face used when mouse is over a citation key."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'face
-  :safe t)
+  :safe #'facep)
 
 
 ;;; Internal variables
diff --git a/lisp/oc-biblatex.el b/lisp/oc-biblatex.el
index 224abaeee..f517e3913 100644
--- a/lisp/oc-biblatex.el
+++ b/lisp/oc-biblatex.el
@@ -80,7 +80,7 @@ If \"biblatex\" package is already required in the document, e.g., through
   :type '(choice
           (string :tag "Options (key=value,key2=value2...)")
           (const :tag "No option" nil))
-  :safe t)
+  :safe #'string-or-null-p)
 
 
 ;;; Internal functions
diff --git a/lisp/oc-csl.el b/lisp/oc-csl.el
index 4378ab595..a7f9e8e75 100644
--- a/lisp/oc-csl.el
+++ b/lisp/oc-csl.el
@@ -146,7 +146,7 @@ directory.  This variable is ignored when style file is absolute."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'boolean
-  :safe t)
+  :safe #'booleanp)
 
 (defcustom org-cite-csl-no-citelinks-backends '(ascii)
   "List of export back-ends for which cite linking is disabled.
@@ -163,7 +163,7 @@ is also disabled."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'string
-  :safe t)
+  :safe #'stringp)
 
 (defcustom org-cite-csl-html-label-width-per-char "0.6em"
   "Character width in CSS units for calculating entry label widths.
@@ -171,14 +171,14 @@ Used only when `second-field-align' is activated by the used CSL style."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'string
-  :safe t)
+  :safe #'stringp)
 
 (defcustom org-cite-csl-latex-hanging-indent "1.5em"
   "Size of hanging-indent for LaTeX output in valid LaTeX units."
   :group 'org-cite
   :package-version '(Org . "9.5")
   :type 'string
-  :safe t)
+  :safe #'stringp)
 
 
 ;;; Internal variables
diff --git a/lisp/oc.el b/lisp/oc.el
index bb2e04d40..556275336 100644
--- a/lisp/oc.el
+++ b/lisp/oc.el
@@ -234,7 +234,7 @@ When nil, the note number is not moved."
   :package-version '(Org . "9.5")
   :type '(choice (const :tag "Automatic note number location" t)
                  (const :tag "Place note numbers manually" nil))
-  :safe t)
+  :safe #'booleanp)
 
 (defcustom org-cite-note-rules
   '(("en-us" inside outside after)
diff --git a/lisp/org-keys.el b/lisp/org-keys.el
index 2984a4f51..8fa551ad4 100644
--- a/lisp/org-keys.el
+++ b/lisp/org-keys.el
@@ -300,7 +300,7 @@ implementation is bad."
 In tables, the special behavior of RET has precedence."
   :group 'org-link-follow
   :type 'boolean
-  :safe t)
+  :safe #'booleanp)
 
 
 ;;; Functions
diff --git a/lisp/org.el b/lisp/org.el
index b67329fc1..bc0ea24be 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -3630,7 +3630,7 @@ When this is non-nil, the headline after the keyword is set to the
   :group 'org-appearance
   :package-version '(Org . "9.4")
   :type 'boolean
-  :safe t)
+  :safe #'booleanp)
 
 (defcustom org-fontify-done-headline t
   "Non-nil means change the face of a headline if it is marked DONE.
diff --git a/lisp/ox-html.el b/lisp/ox-html.el
index 60bb77d81..a150b1fdb 100644
--- a/lisp/ox-html.el
+++ b/lisp/ox-html.el
@@ -795,7 +795,7 @@ Most common values are:
   :group 'org-export-html
   :package-version '(Org . "9.4")
   :type 'string
-  :safe t)
+  :safe #'stringp)
 
 (defcustom org-html-with-latex org-export-with-latex
   "Non-nil means process LaTeX math snippets.
@@ -903,7 +903,7 @@ numbers are enabled."
   :group 'org-export-html
   :package-version '(Org . "9.3")
   :type 'boolean
-  :safe t)
+  :safe #'booleanp)
 
 ;;;; Table
 
diff --git a/lisp/ox-latex.el b/lisp/ox-latex.el
index 993c2c643..3e3967033 100644
--- a/lisp/ox-latex.el
+++ b/lisp/ox-latex.el
@@ -413,7 +413,7 @@ to \"\\autoref{%s}\" or \"\\cref{%s}\" for example."
   :group 'org-export-latex
   :type 'string
   :package-version '(Org . "9.5")
-  :safe t)
+  :safe #'stringp)
 
 ;;;; Preamble
 
@@ -793,7 +793,7 @@ default we use here encompasses both."
   :group 'org-export-latex
   :package-version '(Org . "9.5")
   :type 'string
-  :safe t)
+  :safe #'stringp)
 
 (defcustom org-latex-default-table-mode 'table
   "Default mode for tables.