diff --git a/src/bignum.h b/src/bignum.h
index 132fa31f0f5..9be3a41fd35 100644
--- a/src/bignum.h
+++ b/src/bignum.h
@@ -56,7 +56,7 @@ extern void emacs_mpz_mul_2exp (mpz_t, mpz_t const, EMACS_INT)
   ARG_NONNULL ((1, 2));
 extern void emacs_mpz_pow_ui (mpz_t, mpz_t const, unsigned long)
   ARG_NONNULL ((1, 2));
-extern double mpz_get_d_rounded (mpz_t const) ATTRIBUTE_PURE;
+extern double mpz_get_d_rounded (mpz_t const);
 extern Lisp_Object get_random_bignum (struct Lisp_Bignum const *);
 
 INLINE_HEADER_BEGIN
diff --git a/src/fns.c b/src/fns.c
index 7d3c941a936..157022a5c44 100644
--- a/src/fns.c
+++ b/src/fns.c
@@ -242,8 +242,7 @@ counted.  */)
 
 DEFUN ("proper-list-p", Fproper_list_p, Sproper_list_p, 1, 1, 0,
        doc: /* Return OBJECT's length if it is a proper list, nil otherwise.
-A proper list is neither circular nor dotted (i.e., its last cdr is nil).  */
-       attributes: pure)
+A proper list is neither circular nor dotted (i.e., its last cdr is nil).  */)
   (Lisp_Object object)
 {
   ptrdiff_t len = 0;
diff --git a/src/gnutls.c b/src/gnutls.c
index 247cc7ff3fe..31827280b48 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -1002,8 +1002,7 @@ See also `gnutls-boot'.  */)
 DEFUN ("gnutls-errorp", Fgnutls_errorp, Sgnutls_errorp, 1, 1, 0,
        doc: /* Return t if ERROR indicates a GnuTLS problem.
 ERROR is an integer or a symbol with an integer `gnutls-code' property.
-usage: (gnutls-errorp ERROR)  */
-       attributes: pure)
+usage: (gnutls-errorp ERROR)  */)
   (Lisp_Object err)
 {
   if (EQ (err, Qt)
diff --git a/src/lisp.h b/src/lisp.h
index fe8e2aaea72..0d457345d85 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -619,13 +619,13 @@ INLINE void set_sub_char_table_contents (Lisp_Object, ptrdiff_t,
 /* Defined in bignum.c.  */
 extern int check_int_nonnegative (Lisp_Object);
 extern intmax_t check_integer_range (Lisp_Object, intmax_t, intmax_t);
-extern double bignum_to_double (Lisp_Object) ATTRIBUTE_PURE;
+extern double bignum_to_double (Lisp_Object);
 extern Lisp_Object make_bigint (intmax_t);
 extern Lisp_Object make_biguint (uintmax_t);
 extern uintmax_t check_uinteger_max (Lisp_Object, uintmax_t);
 
 /* Defined in chartab.c.  */
-extern Lisp_Object char_table_ref (Lisp_Object, int) ATTRIBUTE_PURE;
+extern Lisp_Object char_table_ref (Lisp_Object, int);
 extern void char_table_set (Lisp_Object, int, Lisp_Object);
 
 /* Defined in data.c.  */
@@ -4105,9 +4105,9 @@ set_sub_char_table_contents (Lisp_Object table, ptrdiff_t idx, Lisp_Object val)
 
 /* Defined in bignum.c.  This part of bignum.c's API does not require
    the caller to access bignum internals; see bignum.h for that.  */
-extern intmax_t bignum_to_intmax (Lisp_Object) ATTRIBUTE_PURE;
-extern uintmax_t bignum_to_uintmax (Lisp_Object) ATTRIBUTE_PURE;
-extern ptrdiff_t bignum_bufsize (Lisp_Object, int) ATTRIBUTE_PURE;
+extern intmax_t bignum_to_intmax (Lisp_Object);
+extern uintmax_t bignum_to_uintmax (Lisp_Object);
+extern ptrdiff_t bignum_bufsize (Lisp_Object, int);
 extern ptrdiff_t bignum_to_c_string (char *, ptrdiff_t, Lisp_Object, int);
 extern Lisp_Object bignum_to_string (Lisp_Object, int);
 extern Lisp_Object make_bignum_str (char const *, int);