diff --git a/lib/cretonne/src/ir/dfg.rs b/lib/cretonne/src/ir/dfg.rs
index 4a98fc6902..83a32f7ff8 100644
--- a/lib/cretonne/src/ir/dfg.rs
+++ b/lib/cretonne/src/ir/dfg.rs
@@ -660,14 +660,14 @@ impl DataFlowGraph {
 impl Index<Inst> for DataFlowGraph {
     type Output = InstructionData;
 
-    fn index<'a>(&'a self, inst: Inst) -> &'a InstructionData {
+    fn index(&self, inst: Inst) -> &InstructionData {
         &self.insts[inst]
     }
 }
 
 /// Allow mutable access to instructions via indexing.
 impl IndexMut<Inst> for DataFlowGraph {
-    fn index_mut<'a>(&'a mut self, inst: Inst) -> &'a mut InstructionData {
+    fn index_mut(&mut self, inst: Inst) -> &mut InstructionData {
         &mut self.insts[inst]
     }
 }
diff --git a/lib/cretonne/src/ir/instructions.rs b/lib/cretonne/src/ir/instructions.rs
index 2a8d5cdf2d..6c101d751e 100644
--- a/lib/cretonne/src/ir/instructions.rs
+++ b/lib/cretonne/src/ir/instructions.rs
@@ -289,13 +289,13 @@ impl VariableArgs {
 impl Deref for VariableArgs {
     type Target = [Value];
 
-    fn deref<'a>(&'a self) -> &'a [Value] {
+    fn deref(&self) -> &[Value] {
         &self.0
     }
 }
 
 impl DerefMut for VariableArgs {
-    fn deref_mut<'a>(&'a mut self) -> &'a mut [Value] {
+    fn deref_mut(&mut self) -> &mut [Value] {
         &mut self.0
     }
 }