diff --git a/Cargo.toml b/Cargo.toml
index 10858f8..1849005 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 
 name = "rand"
-version = "0.3.0"
+version = "0.3.1"
 authors = ["The Rust Project Developers"]
 license = "MIT/Apache-2.0"
 readme = "README.md"
diff --git a/src/os.rs b/src/os.rs
index 8cb5a51..6037bed 100644
--- a/src/os.rs
+++ b/src/os.rs
@@ -325,7 +325,8 @@
                                v.as_mut_ptr())
             };
             if ret == 0 {
-                panic!("couldn't generate random bytes: {}", os::last_os_error());
+                panic!("couldn't generate random bytes: {}",
+                       io::Error::last_os_error());
             }
         }
     }
@@ -336,7 +337,8 @@
                 CryptReleaseContext(self.hcryptprov, 0)
             };
             if ret == 0 {
-                panic!("couldn't release context: {}", os::last_os_error());
+                panic!("couldn't release context: {}",
+                       io::Error::last_os_error());
             }
         }
     }