diff --git a/src/crypto/hash.rs b/src/crypto/hash.rs
index 37573368..2a181526 100644
--- a/src/crypto/hash.rs
+++ b/src/crypto/hash.rs
@@ -135,7 +135,7 @@ mod tests {
     }
 
     fn compare(calced_raw: Vec<u8>, hashtest: &HashTest) {
-        let calced = calced_raw.as_slice().to_hex().into_string();
+        let calced = calced_raw.as_slice().to_hex().to_string();
 
         if calced != hashtest.expected_output {
             println!("Test failed - {} != {}", calced, hashtest.expected_output);
diff --git a/src/ssl/mod.rs b/src/ssl/mod.rs
index b0db32ea..43673596 100644
--- a/src/ssl/mod.rs
+++ b/src/ssl/mod.rs
@@ -93,8 +93,9 @@ fn get_verify_data_idx<T>() -> c_int {
 
     unsafe {
         INIT.doit(|| {
+            let f: ffi::CRYPTO_EX_free = free_data_box::<T>;
             let idx = ffi::SSL_CTX_get_ex_new_index(0, ptr::null(), None,
-                                                    None, Some(free_data_box::<T>));
+                                                    None, Some(f));
             assert!(idx >= 0);
             VERIFY_DATA_IDX = idx;
         });
@@ -199,7 +200,9 @@ impl SslContext {
         unsafe {
             ffi::SSL_CTX_set_ex_data(self.ctx, VERIFY_IDX,
                                      mem::transmute(verify));
-            ffi::SSL_CTX_set_verify(self.ctx, mode as c_int, Some(raw_verify));
+            let f: extern fn(c_int, *mut ffi::X509_STORE_CTX) -> c_int =
+                                raw_verify;
+            ffi::SSL_CTX_set_verify(self.ctx, mode as c_int, Some(f));
         }
     }
 
@@ -216,7 +219,9 @@ impl SslContext {
                                      mem::transmute(Some(verify)));
             ffi::SSL_CTX_set_ex_data(self.ctx, get_verify_data_idx::<T>(),
                                      mem::transmute(data));
-            ffi::SSL_CTX_set_verify(self.ctx, mode as c_int, Some(raw_verify_with_data::<T>));
+            let f: extern fn(c_int, *mut ffi::X509_STORE_CTX) -> c_int =
+                                raw_verify_with_data::<T>;
+            ffi::SSL_CTX_set_verify(self.ctx, mode as c_int, Some(f));
         }
     }
 
diff --git a/src/ssl/tests.rs b/src/ssl/tests.rs
index 127b87d1..6723fa58 100644
--- a/src/ssl/tests.rs
+++ b/src/ssl/tests.rs
@@ -1,10 +1,11 @@
 use serialize::hex::FromHex;
-use std::io::{Writer};
 use std::io::net::tcp::TcpStream;
+use std::io::{Writer};
+use std::thread::Thread;
 
 use crypto::hash::HashType::{SHA256};
 use ssl::SslMethod::Sslv23;
-use ssl::{SslContext, SslStream};
+use ssl::{SslContext, SslStream, VerifyCallback};
 use ssl::SslVerifyMode::SslVerifyPeer;
 use x509::{X509StoreContext};
 
@@ -52,7 +53,7 @@ fn test_verify_untrusted_callback_override_ok() {
     }
     let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
     let mut ctx = SslContext::new(Sslv23).unwrap();
-    ctx.set_verify(SslVerifyPeer, Some(callback));
+    ctx.set_verify(SslVerifyPeer, Some(callback as VerifyCallback));
     match SslStream::new(&ctx, stream) {
         Ok(_) => (),
         Err(err) => panic!("Expected success, got {}", err)
@@ -66,7 +67,7 @@ fn test_verify_untrusted_callback_override_bad() {
     }
     let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
     let mut ctx = SslContext::new(Sslv23).unwrap();
-    ctx.set_verify(SslVerifyPeer, Some(callback));
+    ctx.set_verify(SslVerifyPeer, Some(callback as VerifyCallback));
     assert!(SslStream::new(&ctx, stream).is_err());
 }
 
@@ -77,7 +78,7 @@ fn test_verify_trusted_callback_override_ok() {
     }
     let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
     let mut ctx = SslContext::new(Sslv23).unwrap();
-    ctx.set_verify(SslVerifyPeer, Some(callback));
+    ctx.set_verify(SslVerifyPeer, Some(callback as VerifyCallback));
     match ctx.set_CA_file(&Path::new("test/cert.pem")) {
         None => {}
         Some(err) => panic!("Unexpected error {}", err)
@@ -95,7 +96,7 @@ fn test_verify_trusted_callback_override_bad() {
     }
     let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
     let mut ctx = SslContext::new(Sslv23).unwrap();
-    ctx.set_verify(SslVerifyPeer, Some(callback));
+    ctx.set_verify(SslVerifyPeer, Some(callback as VerifyCallback));
     match ctx.set_CA_file(&Path::new("test/cert.pem")) {
         None => {}
         Some(err) => panic!("Unexpected error {}", err)
@@ -111,7 +112,7 @@ fn test_verify_callback_load_certs() {
     }
     let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
     let mut ctx = SslContext::new(Sslv23).unwrap();
-    ctx.set_verify(SslVerifyPeer, Some(callback));
+    ctx.set_verify(SslVerifyPeer, Some(callback as VerifyCallback));
     assert!(SslStream::new(&ctx, stream).is_ok());
 }
 
@@ -123,7 +124,7 @@ fn test_verify_trusted_get_error_ok() {
     }
     let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
     let mut ctx = SslContext::new(Sslv23).unwrap();
-    ctx.set_verify(SslVerifyPeer, Some(callback));
+    ctx.set_verify(SslVerifyPeer, Some(callback as VerifyCallback));
     match ctx.set_CA_file(&Path::new("test/cert.pem")) {
         None => {}
         Some(err) => panic!("Unexpected error {}", err)
@@ -139,7 +140,7 @@ fn test_verify_trusted_get_error_err() {
     }
     let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
     let mut ctx = SslContext::new(Sslv23).unwrap();
-    ctx.set_verify(SslVerifyPeer, Some(callback));
+    ctx.set_verify(SslVerifyPeer, Some(callback as VerifyCallback));
     assert!(SslStream::new(&ctx, stream).is_err());
 }
 
@@ -198,7 +199,7 @@ fn test_clone() {
     let stream = TcpStream::connect("127.0.0.1:15418").unwrap();
     let mut stream = SslStream::new(&SslContext::new(Sslv23).unwrap(), stream).unwrap();
     let mut stream2 = stream.clone();
-    spawn(move || {
+    let _t = Thread::spawn(move || {
         stream2.write("GET /\r\n\r\n".as_bytes()).unwrap();
         stream2.flush().unwrap();
     });