diff --git a/lib/msun/man/cospi.3 b/lib/msun/man/cospi.3
--- a/lib/msun/man/cospi.3
+++ b/lib/msun/man/cospi.3
@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd April 1, 2017
+.Dd November 16, 2025
 .Dt COSPI 3
 .Os
 .Sh NAME
@@ -92,12 +92,9 @@
 .An Steven G. Kargl Aq Mt kargl@FreeBSD.org .
 .Sh STANDARDS
 These functions conform to
-IEEE Std 754\(tm\(en2008 ,
-\(dqIEEE Standard for Floating-Point Arithmetic\(dq
-and to
-ISO/IEC TS 18661-4 ,
+.St -ieee754-2008 ,
+to ISO/IEC TS 18661-4,
 \(dqInformation technology \(em Programming languages, their environments,
 and system software interfaces \(em Floating\(enpoint extensions for
-C\(dq \(em Part 4: Supplementary functions.
-
-
+C\(dq \(em Part 4: Supplementary functions, and to
+.St -isoC-2023 .
diff --git a/lib/msun/man/sinpi.3 b/lib/msun/man/sinpi.3
--- a/lib/msun/man/sinpi.3
+++ b/lib/msun/man/sinpi.3
@@ -22,7 +22,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd April 1, 2017
+.Dd November 16, 2025
 .Dt SINPI 3
 .Os
 .Sh NAME
@@ -86,11 +86,9 @@
 .An Steven G. Kargl Aq Mt kargl@FreeBSD.org .
 .Sh STANDARDS
 These functions conform to
-IEEE Std 754\(tm\(en2008 ,
-\(dqIEEE Standard for Floating-Point Arithmetic\(dq
-and to
-ISO/IEC TS 18661-4 ,
+.St -ieee754-2008 ,
+to ISO/IEC TS 18661-4,
 \(dqInformation technology \(em Programming languages, their environments,
 and system software interfaces \(em Floating\(enpoint extensions for
-C\(dq \(em Part 4: Supplementary functions.
-
+C\(dq \(em Part 4: Supplementary functions, and to
+.St -isoC-2023 .
diff --git a/lib/msun/man/tanpi.3 b/lib/msun/man/tanpi.3
--- a/lib/msun/man/tanpi.3
+++ b/lib/msun/man/tanpi.3
@@ -88,12 +88,9 @@
 .An Steven G. Kargl Aq Mt kargl@FreeBSD.org .
 .Sh STANDARDS
 These functions conform to
-IEEE Std 754\(tm\(en2008 ,
-\(dqIEEE Standard for Floating-Point Arithmetic\(dq
-and to
-ISO/IEC TS 18661-4 ,
+.St -ieee754-2008 ,
+to ISO/IEC TS 18661-4,
 \(dqInformation technology \(em Programming languages, their environments,
 and system software interfaces \(em Floating\(enpoint extensions for
-C\(dq \(em Part 4: Supplementary functions.
-
-
+C\(dq \(em Part 4: Supplementary functions, and to
+.St -isoC-2023 .
diff --git a/lib/msun/src/math.h b/lib/msun/src/math.h
--- a/lib/msun/src/math.h
+++ b/lib/msun/src/math.h
@@ -508,6 +508,9 @@
 void		sincos(double, double *, double *);
 void		sincosf(float, float *, float *);
 void		sincosl(long double, long double *, long double *);
+#endif /* __BSD_VISIBLE */
+
+#if __ISO_C_VISIBLE >= 2023
 double		cospi(double);
 float		cospif(float);
 long double 	cospil(long double);
@@ -517,7 +520,7 @@
 double		tanpi(double);
 float		tanpif(float);
 long double	tanpil(long double);
-#endif
+#endif /* __ISO_C_VISIBLE >= 2023 */
 
 __END_DECLS