diff --git a/man2/sigprocmask.2 b/man2/sigprocmask.2
index a622e4c18..b82386f14 100644
--- a/man2/sigprocmask.2
+++ b/man2/sigprocmask.2
@@ -37,12 +37,16 @@ sigprocmask, rt_sigprocmask \- examine and change blocked signals
 .BI "int sigprocmask(int " how ", const sigset_t *restrict " set ,
 .BI "                sigset_t *restrict " oldset );
 .PP
+.BR "#include <signal.h>" "           /* Definition of " SIG_* " constants */"
+.BR "#include <sys/syscall.h>" "      /* Definition of " SYS_* " constants */"
+.B #include <unistd.h>
+.PP
 /* Prototype for the underlying system call */
-.BI "int rt_sigprocmask(int " how ", const kernel_sigset_t *" set ,
+.BI "int syscall(SYS_rt_sigprocmask, int " how ", const kernel_sigset_t *" set ,
 .BI "                kernel_sigset_t *" oldset ", size_t " sigsetsize );
 .PP
 /* Prototype for the legacy system call (deprecated) */
-.BI "int sigprocmask(int " how ", const old_kernel_sigset_t *" set ,
+.BI "int syscall(SYS_sigprocmask, int " how ", const old_kernel_sigset_t *" set ,
 .BI "                old_kernel_sigset_t *" oldset );
 .fi
 .PP