diff --git a/openssl-sys/src/lib.rs b/openssl-sys/src/lib.rs
index 784b7637e1..0e23386fd3 100644
--- a/openssl-sys/src/lib.rs
+++ b/openssl-sys/src/lib.rs
@@ -11,7 +11,7 @@
 #![recursion_limit = "128"] // configure fixed limit across all rust versions
 
 extern crate libc;
-pub use libc::*;
+pub use libc::c_int;
 
 #[cfg(feature = "unstable_boringssl")]
 extern crate bssl_sys;
diff --git a/openssl/src/bn.rs b/openssl/src/bn.rs
index c75fac1d70..a67d0807aa 100644
--- a/openssl/src/bn.rs
+++ b/openssl/src/bn.rs
@@ -1229,7 +1229,7 @@ impl Ord for BigNumRef {
 
 impl PartialOrd for BigNum {
     fn partial_cmp(&self, oth: &BigNum) -> Option<Ordering> {
-        self.deref().partial_cmp(oth.deref())
+        Some(self.cmp(oth))
     }
 }
 
diff --git a/openssl/src/x509/mod.rs b/openssl/src/x509/mod.rs
index d211006b78..97242ff4d8 100644
--- a/openssl/src/x509/mod.rs
+++ b/openssl/src/x509/mod.rs
@@ -832,7 +832,7 @@ impl Ord for X509 {
 
 impl PartialOrd for X509 {
     fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
-        X509Ref::partial_cmp(self, other)
+        Some(self.cmp(other))
     }
 }
 
diff --git a/systest/Cargo.toml b/systest/Cargo.toml
index 97a5405b0e..d1e55ac3f2 100644
--- a/systest/Cargo.toml
+++ b/systest/Cargo.toml
@@ -9,7 +9,7 @@ libc = "0.2"
 openssl-sys = { path = "../openssl-sys" }
 
 [build-dependencies]
-ctest2 = "0.4"
+ctest2 = "0.4.7"
 
 [features]
 vendored = ['openssl-sys/vendored']