diff --git a/src/liblibc b/src/liblibc
index 7e33065ce4975..68f9959e53da6 160000
--- a/src/liblibc
+++ b/src/liblibc
@@ -1 +1 @@
-Subproject commit 7e33065ce49759958c0d1c04fcadef961032a943
+Subproject commit 68f9959e53da6c70bed7119cd09342859d431266
diff --git a/src/libstd/sys/unix/rand.rs b/src/libstd/sys/unix/rand.rs
index fd066c9cdbeef..e2d40742c7136 100644
--- a/src/libstd/sys/unix/rand.rs
+++ b/src/libstd/sys/unix/rand.rs
@@ -49,7 +49,9 @@ mod imp {
                   target_arch = "powerpc64",
                   target_arch = "s390x")))]
     fn getrandom(buf: &mut [u8]) -> libc::c_long {
-        #[cfg(target_arch = "x86_64")]
+        #[cfg(all(target_arch = "x86_64", target_pointer_width = "32"))]
+        const NR_GETRANDOM: libc::c_long = 0x40000000 + 318;
+        #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))]
         const NR_GETRANDOM: libc::c_long = 318;
         #[cfg(target_arch = "x86")]
         const NR_GETRANDOM: libc::c_long = 355;