diff --git a/src/base64/base64.rs b/src/base64/base64.rs
index 817632bc4..e09b08c18 100644
--- a/src/base64/base64.rs
+++ b/src/base64/base64.rs
@@ -96,7 +96,7 @@ pub fn uumain(args: Vec<String>) -> int {
 }
 
 fn decode(input: &mut Reader, ignore_garbage: bool) {
-    let mut to_decode = match input.read_to_string() {
+    let to_decode = match input.read_to_string() {
         Ok(m) => m,
         Err(f) => panic!(f)
     };
diff --git a/src/common/c_types.rs b/src/common/c_types.rs
index ae2580922..ea4818b7c 100644
--- a/src/common/c_types.rs
+++ b/src/common/c_types.rs
@@ -47,6 +47,8 @@ pub struct c_passwd {
     pub pw_shell:   *const c_char,
 }
 
+impl Copy for c_passwd {}
+
 #[cfg(any(target_os = "macos", target_os = "freebsd"))]
 #[repr(C)]
 pub struct utsname {
@@ -68,6 +70,8 @@ pub struct utsname {
     pub domainame: [c_char, ..65]
 }
 
+impl Copy for utsname {}
+
 #[repr(C)]
 pub struct c_group {
     pub gr_name:   *const c_char,  // group name
@@ -76,6 +80,8 @@ pub struct c_group {
     pub gr_mem:    *const *const c_char, // member list
 }
 
+impl Copy for c_group {}
+
 #[repr(C)]
 pub struct c_tm {
     pub tm_sec: c_int,         /* seconds */
@@ -89,6 +95,8 @@ pub struct c_tm {
     pub tm_isdst: c_int       /* daylight saving time */
 }
 
+impl Copy for c_tm {}
+
 extern {
     pub fn getpwuid(uid: uid_t) -> *const c_passwd;
     pub fn getpwnam(login: *const c_char) -> *const c_passwd;
diff --git a/src/cp/cp.rs b/src/cp/cp.rs
index 52dc096d3..4e3826c59 100644
--- a/src/cp/cp.rs
+++ b/src/cp/cp.rs
@@ -31,6 +31,8 @@ pub enum Mode {
     Version,
 }
 
+impl Copy for Mode {}
+
 pub fn uumain(args: Vec<String>) -> int {
     let opts = [
         optflag("h", "help", "display this help and exit"),
diff --git a/src/fmt/linebreak.rs b/src/fmt/linebreak.rs
index fc0214e56..f7f6b6c27 100644
--- a/src/fmt/linebreak.rs
+++ b/src/fmt/linebreak.rs
@@ -322,7 +322,7 @@ fn build_best_path<'a>(paths: &Vec<LineBreak<'a>>, active: &Vec<uint>) -> Vec<(&
     // now, chase the pointers back through the break list, recording
     // the words at which we should break
     loop {
-        let next_best = paths[best_idx];
+        let ref next_best = paths[best_idx];
         match next_best.linebreak {
             None => return breakwords,
             Some(prev) => {
diff --git a/src/hostid/hostid.rs b/src/hostid/hostid.rs
index eeb899429..05dc6dabf 100644
--- a/src/hostid/hostid.rs
+++ b/src/hostid/hostid.rs
@@ -42,6 +42,8 @@ pub enum Mode {
     Version,
 }
 
+impl Copy for Mode {}
+
 //currently rust libc interface doesn't include gethostid
 extern {
     pub fn gethostid() -> c_long;
diff --git a/src/kill/kill.rs b/src/kill/kill.rs
index 17a71f4c1..6ed91df25 100644
--- a/src/kill/kill.rs
+++ b/src/kill/kill.rs
@@ -52,6 +52,8 @@ pub enum Mode {
     Version,
 }
 
+impl Copy for Mode {}
+
 pub fn uumain(args: Vec<String>) -> int {
     let opts = [
         optflag("h", "help", "display this help and exit"),
diff --git a/src/mv/mv.rs b/src/mv/mv.rs
index 02e770e10..e3dabd008 100644
--- a/src/mv/mv.rs
+++ b/src/mv/mv.rs
@@ -49,6 +49,8 @@ pub enum OverwriteMode {
     Force,
 }
 
+impl Copy for OverwriteMode {}
+
 #[deriving(Eq, PartialEq)]
 pub enum BackupMode {
     NoBackup,
@@ -57,6 +59,8 @@ pub enum BackupMode {
     ExistingBackup,
 }
 
+impl Copy for BackupMode {}
+
 pub fn uumain(args: Vec<String>) -> int {
     let program = args[0].as_slice();
     let opts = [
diff --git a/src/rm/rm.rs b/src/rm/rm.rs
index 2433dcaee..f5d13030c 100644
--- a/src/rm/rm.rs
+++ b/src/rm/rm.rs
@@ -27,6 +27,8 @@ enum InteractiveMode {
     InteractiveAlways
 }
 
+impl Copy for InteractiveMode {}
+
 static NAME: &'static str = "rm";
 
 pub fn uumain(args: Vec<String>) -> int {
diff --git a/src/test/test.rs b/src/test/test.rs
index 97bb9bcf9..6db9d0787 100644
--- a/src/test/test.rs
+++ b/src/test/test.rs
@@ -199,6 +199,8 @@ enum Precedence {
     UnOp
 }
 
+impl Copy for Precedence {}
+
 fn parse_expr(mut args: &[&[u8]], error: &mut bool) -> bool {
     if args.len() == 0 {
         false