diff --git a/lib/cretonne/src/bforest/mod.rs b/lib/cretonne/src/bforest/mod.rs
index b1d4aa3c28..ff1b94cc0f 100644
--- a/lib/cretonne/src/bforest/mod.rs
+++ b/lib/cretonne/src/bforest/mod.rs
@@ -97,7 +97,7 @@ trait Forest {
 }
 
 /// A reference to a B+-tree node.
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Clone, Copy, PartialEq, Eq)]
 struct Node(u32);
 entity_impl!(Node, "node");
 
diff --git a/lib/cretonne/src/entity/mod.rs b/lib/cretonne/src/entity/mod.rs
index 4fc40ea56e..837bb5f107 100644
--- a/lib/cretonne/src/entity/mod.rs
+++ b/lib/cretonne/src/entity/mod.rs
@@ -87,5 +87,11 @@ macro_rules! entity_impl {
                 write!(f, "{}{}", $display_prefix, self.0)
             }
         }
+
+        impl ::std::fmt::Debug for $entity {
+            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+            	(self as &::std::fmt::Display).fmt(f)
+			}
+		}
     }
 }
diff --git a/lib/cretonne/src/ir/entities.rs b/lib/cretonne/src/ir/entities.rs
index 4060e6ff37..4a4a40df42 100644
--- a/lib/cretonne/src/ir/entities.rs
+++ b/lib/cretonne/src/ir/entities.rs
@@ -23,7 +23,7 @@ use std::fmt;
 use std::u32;
 
 /// An opaque reference to an extended basic block in a function.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, PartialOrd, Ord)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct Ebb(u32);
 entity_impl!(Ebb, "ebb");
 
@@ -37,7 +37,7 @@ impl Ebb {
 }
 
 /// An opaque reference to an SSA value.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, PartialOrd, Ord)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct Value(u32);
 entity_impl!(Value, "v");
 
@@ -56,17 +56,17 @@ impl Value {
 }
 
 /// An opaque reference to an instruction in a function.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, PartialOrd, Ord)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct Inst(u32);
 entity_impl!(Inst, "inst");
 
 /// An opaque reference to a stack slot.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct StackSlot(u32);
 entity_impl!(StackSlot, "ss");
 
 /// An opaque reference to a global variable.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct GlobalVar(u32);
 entity_impl!(GlobalVar, "gv");
 
@@ -84,27 +84,27 @@ impl GlobalVar {
 }
 
 /// An opaque reference to a jump table.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct JumpTable(u32);
 entity_impl!(JumpTable, "jt");
 
 /// A reference to an external function.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct FuncRef(u32);
 entity_impl!(FuncRef, "fn");
 
 /// A reference to a function signature.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct SigRef(u32);
 entity_impl!(SigRef, "sig");
 
 /// A reference to a heap.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Heap(u32);
 entity_impl!(Heap, "heap");
 
 /// A reference to any of the entities defined in this module.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub enum AnyEntity {
     /// The whole function.
     Function,
@@ -145,6 +145,12 @@ impl fmt::Display for AnyEntity {
     }
 }
 
+impl fmt::Debug for AnyEntity {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        (self as &fmt::Display).fmt(f)
+    }
+}
+
 impl From<Ebb> for AnyEntity {
     fn from(r: Ebb) -> AnyEntity {
         AnyEntity::Ebb(r)
diff --git a/lib/cretonne/src/loop_analysis.rs b/lib/cretonne/src/loop_analysis.rs
index e6390aa100..ad3239f5e5 100644
--- a/lib/cretonne/src/loop_analysis.rs
+++ b/lib/cretonne/src/loop_analysis.rs
@@ -9,7 +9,7 @@ use ir::{Function, Ebb, Layout};
 use packed_option::PackedOption;
 
 /// A opaque reference to a code loop.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct Loop(u32);
 entity_impl!(Loop, "loop");
 
diff --git a/lib/cretonne/src/regalloc/virtregs.rs b/lib/cretonne/src/regalloc/virtregs.rs
index c2cb6c8ffe..852f1e0af0 100644
--- a/lib/cretonne/src/regalloc/virtregs.rs
+++ b/lib/cretonne/src/regalloc/virtregs.rs
@@ -18,7 +18,7 @@ use packed_option::PackedOption;
 use ref_slice::ref_slice;
 
 /// A virtual register reference.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, PartialOrd, Ord)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub struct VirtReg(u32);
 entity_impl!(VirtReg, "vreg");