diff --git a/src/conversion.rs b/src/conversion.rs
index 0c9574b..5a1a1bf 100644
--- a/src/conversion.rs
+++ b/src/conversion.rs
@@ -42,7 +42,6 @@ impl<'lua> FromLua<'lua> for Table<'lua> {
             _ => Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "table",
-                expected: None,
                 message: None,
             }),
         }
@@ -62,7 +61,6 @@ impl<'lua> FromLua<'lua> for Function<'lua> {
             _ => Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "function",
-                expected: None,
                 message: None,
             }),
         }
@@ -82,7 +80,6 @@ impl<'lua> FromLua<'lua> for Thread<'lua> {
             _ => Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "thread",
-                expected: None,
                 message: None,
             }),
         }
@@ -102,7 +99,6 @@ impl<'lua> FromLua<'lua> for AnyUserData<'lua> {
             _ => Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "userdata",
-                expected: None,
                 message: None,
             }),
         }
@@ -122,7 +118,6 @@ impl<'lua, T: UserData + Clone> FromLua<'lua> for T {
             _ => Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "userdata",
-                expected: None,
                 message: None,
             }),
         }
@@ -177,7 +172,6 @@ impl<'lua> FromLua<'lua> for LightUserData {
             _ => Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "light userdata",
-                expected: None,
                 message: None,
             }),
         }
@@ -262,8 +256,7 @@ impl<'lua, T: FromLua<'lua>> FromLua<'lua> for Vec<T> {
             Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "Vec",
-                expected: Some("table"),
-                message: None,
+                message: Some("expected table".to_string()),
             })
         }
     }
@@ -283,8 +276,7 @@ impl<'lua, K: Eq + Hash + FromLua<'lua>, V: FromLua<'lua>> FromLua<'lua> for Has
             Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "HashMap",
-                expected: Some("table"),
-                message: None,
+                message: Some("expected table".to_string()),
             })
         }
     }
@@ -304,8 +296,7 @@ impl<'lua, K: Ord + FromLua<'lua>, V: FromLua<'lua>> FromLua<'lua> for BTreeMap<
             Err(Error::FromLuaConversionError {
                 from: value.type_name(),
                 to: "BTreeMap",
-                expected: Some("table"),
-                message: None,
+                message: Some("expected table".to_string()),
             })
         }
     }
diff --git a/src/error.rs b/src/error.rs
index 1509651..73cfd3f 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -42,11 +42,6 @@ pub enum Error {
         from: &'static str,
         /// Name of the Rust type that could not be created.
         to: &'static str,
-        /// A string indicating the possible Lua values/types for this conversion.
-        ///
-        /// To avoid redundancy, this should only be set to `Some` when there are nontrivial rules
-        /// about valid conversions, since the `to` string should already hint at the problem.
-        expected: Option<&'static str>,
         /// A string containing more detailed error information.
         message: Option<String>,
     },
@@ -121,14 +116,11 @@ impl fmt::Display for Error {
                     Some(ref message) => write!(fmt, " ({})", message),
                 }
             }
-            Error::FromLuaConversionError { from, to, ref expected, ref message } => {
+            Error::FromLuaConversionError { from, to, ref message } => {
                 write!(fmt, "error converting Lua {} to {}", from, to)?;
-                match (expected.as_ref(), message.as_ref()) {
-                    (None, None) => Ok(()),
-                    (None, Some(ref message)) => write!(fmt, " ({})", message),
-                    (Some(ref expected), None) => write!(fmt, " (expected {})", expected),
-                    (Some(ref expected), Some(ref message)) =>
-                        write!(fmt, " ({}; expected {})", message, expected),
+                match *message {
+                    None => Ok(()),
+                    Some(ref message) => write!(fmt, " ({})", message),
                 }
             }
             Error::CoroutineInactive => write!(fmt, "cannot resume inactive coroutine"),
diff --git a/src/lua.rs b/src/lua.rs
index 359babc..e422922 100644
--- a/src/lua.rs
+++ b/src/lua.rs
@@ -211,7 +211,6 @@ impl<'lua> String<'lua> {
         str::from_utf8(self.as_bytes()).map_err(|e| Error::FromLuaConversionError {
             from: "string",
             to: "&str",
-            expected: Some("utf-8 string"),
             message: Some(e.to_string()),
         })
     }
@@ -1109,8 +1108,7 @@ impl<'lua, T: UserData> UserDataMethods<'lua, T> {
         } else {
             Err(Error::FromLuaConversionError {
                 from: "missing argument",
-                to: "UserData",
-                expected: Some("userdata"),
+                to: "userdata",
                 message: None,
             })
         })
@@ -1130,8 +1128,7 @@ impl<'lua, T: UserData> UserDataMethods<'lua, T> {
         } else {
             Err(Error::FromLuaConversionError {
                 from: "missing argument",
-                to: "UserData",
-                expected: Some("userdata"),
+                to: "userdata",
                 message: None,
             })
         })
@@ -1643,8 +1640,7 @@ impl Lua {
                         Err(Error::FromLuaConversionError {
                             from: ty,
                             to: "String",
-                            expected: Some("string or number"),
-                            message: None,
+                            message: Some("expected string or number".to_string()),
                         })
                     } else {
                         Ok(String(self.pop_ref(self.state)))
@@ -1673,7 +1669,6 @@ impl Lua {
                         Err(Error::FromLuaConversionError {
                             from: ty,
                             to: "integer",
-                            expected: None,
                             message: None,
                         })
                     } else {
@@ -1703,8 +1698,7 @@ impl Lua {
                         Err(Error::FromLuaConversionError {
                             from: ty,
                             to: "number",
-                            expected: Some("number or string coercible to number"),
-                            message: None,
+                            message: Some("number or string coercible to number".to_string()),
                         })
                     } else {
                         Ok(n)