diff --git a/lib/std/c.zig b/lib/std/c.zig
index e5de565e0..f79901fbe 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -101,7 +101,7 @@ pub extern "c" fn dup(fd: fd_t) c_int;
 pub extern "c" fn dup2(old_fd: fd_t, new_fd: fd_t) c_int;
 pub extern "c" fn readlink(noalias path: [*:0]const u8, noalias buf: [*]u8, bufsize: usize) isize;
 pub extern "c" fn realpath(noalias file_name: [*:0]const u8, noalias resolved_name: [*]u8) ?[*:0]u8;
-pub extern "c" fn sigprocmask(how: c_int, noalias set: *const sigset_t, noalias oset: ?*sigset_t) c_int;
+pub extern "c" fn sigprocmask(how: c_int, noalias set: ?*const sigset_t, noalias oset: ?*sigset_t) c_int;
 pub extern "c" fn gettimeofday(noalias tv: ?*timeval, noalias tz: ?*timezone) c_int;
 pub extern "c" fn sigaction(sig: c_int, noalias act: *const Sigaction, noalias oact: ?*Sigaction) c_int;
 pub extern "c" fn nanosleep(rqtp: *const timespec, rmtp: ?*timespec) c_int;
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 51649941c..1adfa1bab 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -665,7 +665,7 @@ pub fn gettid() i32 {
     return @bitCast(i32, @truncate(u32, syscall0(SYS_gettid)));
 }
 
-pub fn sigprocmask(flags: u32, noalias set: *const sigset_t, noalias oldset: ?*sigset_t) usize {
+pub fn sigprocmask(flags: u32, noalias set: ?*const sigset_t, noalias oldset: ?*sigset_t) usize {
     return syscall4(SYS_rt_sigprocmask, flags, @ptrToInt(set), @ptrToInt(oldset), NSIG / 8);
 }