diff --git a/src/libcore/hash.rs b/src/libcore/hash.rs
index d3d6c5ae242..688cd32a1e0 100644
--- a/src/libcore/hash.rs
+++ b/src/libcore/hash.rs
@@ -169,7 +169,7 @@ struct SipState {
     mut v1: u64,
     mut v2: u64,
     mut v3: u64,
-    tail: [mut u8 * 8], // unprocessed bytes
+    mut tail: [u8 * 8], // unprocessed bytes
     mut ntail: uint,  // how many bytes in tail are valid
 }
 
@@ -183,7 +183,7 @@ fn SipState(key0: u64, key1: u64) -> SipState {
         mut v1 : 0u64,
         mut v2 : 0u64,
         mut v3 : 0u64,
-        tail : [mut 0u8,0,0,0,0,0,0,0],
+        mut tail : [0u8,0,0,0,0,0,0,0],
         mut ntail : 0u,
     };
     (&state).reset();
diff --git a/src/librustc/middle/typeck/infer/region_inference.rs b/src/librustc/middle/typeck/infer/region_inference.rs
index e4041e8f9e0..d928ad264fd 100644
--- a/src/librustc/middle/typeck/infer/region_inference.rs
+++ b/src/librustc/middle/typeck/infer/region_inference.rs
@@ -1237,7 +1237,7 @@ impl RegionVarBindings {
                 classification: Contracting,
                 span: self.var_spans[var_idx],
                 value: NoValue,
-                head_edge: [mut uint::max_value, uint::max_value]
+                head_edge: [uint::max_value, uint::max_value]
             }
         });
 
@@ -1245,7 +1245,7 @@ impl RegionVarBindings {
         let mut edges = vec::with_capacity(num_edges);
         for self.constraints.each_ref |constraint, span| {
             edges.push(GraphEdge {
-                next_edge: [mut uint::max_value, uint::max_value],
+                next_edge: [uint::max_value, uint::max_value],
                 constraint: *constraint,
                 span: *span
             });
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index d41fedebde3..5e5537aedea 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -193,7 +193,7 @@ pub fn Parser(sess: parse_sess,
         token: tok0.tok,
         span: span0,
         last_span: span0,
-        buffer: [mut {tok: tok0.tok, sp: span0}, ..4],
+        mut buffer: [{tok: tok0.tok, sp: span0}, ..4],
         buffer_start: 0,
         buffer_end: 0,
         tokens_consumed: 0u,
@@ -213,7 +213,7 @@ pub struct Parser {
     mut token: token::Token,
     mut span: span,
     mut last_span: span,
-    mut buffer: [mut {tok: token::Token, sp: span} * 4],
+    mut buffer: [{tok: token::Token, sp: span} * 4],
     mut buffer_start: int,
     mut buffer_end: int,
     mut tokens_consumed: uint,