diff --git a/man2/sigprocmask.2 b/man2/sigprocmask.2
index b4899ff8a..ba78ccffd 100644
--- a/man2/sigprocmask.2
+++ b/man2/sigprocmask.2
@@ -34,7 +34,8 @@ sigprocmask, rt_sigprocmask \- examine and change blocked signals
 .PP
 .nf
 /* Prototype for the glibc wrapper function */
-.BI "int sigprocmask(int " how ", const sigset_t *" set ", sigset_t *" oldset );
+.BI "int sigprocmask(int " how ", const sigset_t *restrict " set ,
+.BI "                sigset_t *restrict " oldset );
 .PP
 /* Prototype for the underlying system call */
 .BI "int rt_sigprocmask(int " how ", const kernel_sigset_t *" set ,