diff --git a/src/libcretonne/cfg.rs b/src/libcretonne/cfg.rs
index e9ecd9d982..c2a2b6dcf2 100644
--- a/src/libcretonne/cfg.rs
+++ b/src/libcretonne/cfg.rs
@@ -21,8 +21,8 @@
 //! and (Ebb0, `jmp Ebb2`) respectively.
 
 use repr::Function;
-use entities::{Inst, Ebb};
-use instructions::InstructionData;
+use repr::entities::{Inst, Ebb};
+use repr::instructions::InstructionData;
 use std::collections::{BTreeSet, BTreeMap, btree_map};
 
 /// A basic block denoted by its enclosing Ebb and last instruction.
diff --git a/src/libcretonne/lib.rs b/src/libcretonne/lib.rs
index bc2edd9d59..0b1ac8678e 100644
--- a/src/libcretonne/lib.rs
+++ b/src/libcretonne/lib.rs
@@ -7,14 +7,7 @@
 
 pub const VERSION: &'static str = env!("CARGO_PKG_VERSION");
 
-pub mod types;
-pub mod condcodes;
-pub mod immediates;
-pub mod entities;
-pub mod instructions;
 pub mod repr;
-pub mod dfg;
-pub mod layout;
 pub mod write;
 pub mod cfg;
 
diff --git a/src/libcretonne/condcodes.rs b/src/libcretonne/repr/condcodes.rs
similarity index 100%
rename from src/libcretonne/condcodes.rs
rename to src/libcretonne/repr/condcodes.rs
diff --git a/src/libcretonne/dfg.rs b/src/libcretonne/repr/dfg.rs
similarity index 97%
rename from src/libcretonne/dfg.rs
rename to src/libcretonne/repr/dfg.rs
index 7cfdaa7fbf..29a462f73e 100644
--- a/src/libcretonne/dfg.rs
+++ b/src/libcretonne/repr/dfg.rs
@@ -1,9 +1,9 @@
 //! Data flow graph tracking Instructions, Values, and EBBs.
 
 use entity_map::EntityMap;
-use entities::{Ebb, Inst, Value, NO_VALUE, ExpandedValue};
-use instructions::InstructionData;
-use types::Type;
+use repr::entities::{Ebb, Inst, Value, NO_VALUE, ExpandedValue};
+use repr::instructions::InstructionData;
+use repr::types::Type;
 use std::ops::{Index, IndexMut};
 use std::u16;
 
@@ -57,7 +57,7 @@ impl DataFlowGraph {
 
     /// Get the type of a value.
     pub fn value_type(&self, v: Value) -> Type {
-        use entities::ExpandedValue::*;
+        use repr::entities::ExpandedValue::*;
         match v.expand() {
             Direct(i) => self.insts[i].first_type(),
             Table(i) => {
@@ -75,7 +75,7 @@ impl DataFlowGraph {
     /// This is either the instruction that defined it or the Ebb that has the value as an
     /// argument.
     pub fn value_def(&self, v: Value) -> ValueDef {
-        use entities::ExpandedValue::*;
+        use repr::entities::ExpandedValue::*;
         match v.expand() {
             Direct(inst) => ValueDef::Res(inst, 0),
             Table(idx) => {
@@ -339,8 +339,8 @@ impl EbbData {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use types;
-    use instructions::{Opcode, InstructionData};
+    use repr::types;
+    use repr::instructions::{Opcode, InstructionData};
 
     #[test]
     fn make_inst() {
diff --git a/src/libcretonne/entities.rs b/src/libcretonne/repr/entities.rs
similarity index 100%
rename from src/libcretonne/entities.rs
rename to src/libcretonne/repr/entities.rs
diff --git a/src/libcretonne/immediates.rs b/src/libcretonne/repr/immediates.rs
similarity index 100%
rename from src/libcretonne/immediates.rs
rename to src/libcretonne/repr/immediates.rs
diff --git a/src/libcretonne/instructions.rs b/src/libcretonne/repr/instructions.rs
similarity index 99%
rename from src/libcretonne/instructions.rs
rename to src/libcretonne/repr/instructions.rs
index 8ebd63d411..7ebb71bbf4 100644
--- a/src/libcretonne/instructions.rs
+++ b/src/libcretonne/repr/instructions.rs
@@ -10,10 +10,10 @@ use std::fmt::{self, Display, Formatter};
 use std::str::FromStr;
 use std::ops::{Deref, DerefMut};
 
-use entities::*;
-use immediates::*;
-use condcodes::*;
-use types::{self, Type};
+use repr::entities::*;
+use repr::immediates::*;
+use repr::condcodes::*;
+use repr::types::{self, Type};
 
 // Include code generated by `meta/gen_instr.py`. This file contains:
 //
@@ -560,7 +560,7 @@ mod tests {
 
     #[test]
     fn value_set() {
-        use types::*;
+        use repr::types::*;
 
         let vts = ValueTypeSet {
             allow_scalars: true,
diff --git a/src/libcretonne/layout.rs b/src/libcretonne/repr/layout.rs
similarity index 99%
rename from src/libcretonne/layout.rs
rename to src/libcretonne/repr/layout.rs
index 8ae6657dff..36ee2dacf8 100644
--- a/src/libcretonne/layout.rs
+++ b/src/libcretonne/repr/layout.rs
@@ -5,7 +5,7 @@
 
 use std::iter::{Iterator, IntoIterator};
 use entity_map::{EntityMap, EntityRef};
-use entities::{Ebb, NO_EBB, Inst, NO_INST};
+use repr::entities::{Ebb, NO_EBB, Inst, NO_INST};
 
 /// The `Layout` struct determines the layout of EBBs and instructions in a function. It does not
 /// contain definitions of instructions or EBBs, but depends on `Inst` and `Ebb` entity references
@@ -242,7 +242,7 @@ impl<'a> Iterator for Insts<'a> {
 mod tests {
     use super::Layout;
     use entity_map::EntityRef;
-    use entities::{Ebb, Inst};
+    use repr::entities::{Ebb, Inst};
 
     #[test]
     fn append_ebb() {
diff --git a/src/libcretonne/repr/mod.rs b/src/libcretonne/repr/mod.rs
index 6f7075ae4d..a62527ccbe 100644
--- a/src/libcretonne/repr/mod.rs
+++ b/src/libcretonne/repr/mod.rs
@@ -1,10 +1,18 @@
 //! Representation of Cretonne IL functions.
 
-use types::{FunctionName, Signature};
+pub mod entities;
+pub mod types;
+pub mod condcodes;
+pub mod immediates;
+pub mod instructions;
+pub mod dfg;
+pub mod layout;
+
+use repr::types::{FunctionName, Signature};
 use entity_map::EntityRef;
-use entities::{Ebb, NO_EBB, StackSlot};
-use dfg::DataFlowGraph;
-use layout::Layout;
+use repr::entities::{Ebb, NO_EBB, StackSlot};
+use repr::dfg::DataFlowGraph;
+use repr::layout::Layout;
 use std::fmt::{self, Debug, Display, Formatter};
 use std::ops::Index;
 
diff --git a/src/libcretonne/types.rs b/src/libcretonne/repr/types.rs
similarity index 100%
rename from src/libcretonne/types.rs
rename to src/libcretonne/repr/types.rs
diff --git a/src/libcretonne/test_utils/make_inst.rs b/src/libcretonne/test_utils/make_inst.rs
index 2f45a09cba..00955a5be5 100644
--- a/src/libcretonne/test_utils/make_inst.rs
+++ b/src/libcretonne/test_utils/make_inst.rs
@@ -1,9 +1,9 @@
 //! Helper functions for generating dummy instructions.
 
 use repr::Function;
-use entities::{Ebb, Inst, NO_VALUE};
-use instructions::{InstructionData, Opcode, VariableArgs, JumpData, BranchData};
-use types;
+use repr::entities::{Ebb, Inst, NO_VALUE};
+use repr::instructions::{InstructionData, Opcode, VariableArgs, JumpData, BranchData};
+use repr::types;
 
 pub fn jump(func: &mut Function, dest: Ebb) -> Inst {
     func.dfg.make_inst(InstructionData::Jump {
diff --git a/src/libcretonne/write.rs b/src/libcretonne/write.rs
index 10181e0f63..5b66b81065 100644
--- a/src/libcretonne/write.rs
+++ b/src/libcretonne/write.rs
@@ -6,8 +6,8 @@
 
 use std::io::{self, Write};
 use repr::Function;
-use entities::{Inst, Ebb, Value};
-use types::Type;
+use repr::entities::{Inst, Ebb, Value};
+use repr::types::Type;
 
 pub type Result = io::Result<()>;
 
@@ -182,7 +182,7 @@ pub fn write_instruction(w: &mut Write, func: &Function, inst: Inst) -> Result {
     }
 
     // Then the operands, depending on format.
-    use instructions::InstructionData::*;
+    use repr::instructions::InstructionData::*;
     match func.dfg[inst] {
         Nullary { .. } => writeln!(w, ""),
         Unary { arg, .. } => writeln!(w, " {}", arg),
@@ -218,7 +218,7 @@ mod tests {
     use super::*;
     use super::{needs_quotes, escaped};
     use repr::{Function, StackSlotData};
-    use types;
+    use repr::types;
 
     #[test]
     fn quoting() {
diff --git a/src/libreader/lexer.rs b/src/libreader/lexer.rs
index 4d3dfdf7c1..87c7482589 100644
--- a/src/libreader/lexer.rs
+++ b/src/libreader/lexer.rs
@@ -6,8 +6,8 @@
 // ====--------------------------------------------------------------------------------------====//
 
 use std::str::CharIndices;
-use cretonne::types;
-use cretonne::entities::{Value, Ebb};
+use cretonne::repr::types;
+use cretonne::repr::entities::{Value, Ebb};
 
 /// The location of a `Token` or `Error`.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -373,8 +373,8 @@ impl<'a> Lexer<'a> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use cretonne::types;
-    use cretonne::entities::{Value, Ebb};
+    use cretonne::repr::types;
+    use cretonne::repr::entities::{Value, Ebb};
 
     fn token<'a>(token: Token<'a>, line: usize) -> Option<Result<LocatedToken<'a>, LocatedError>> {
         Some(super::token(token, Location { line_number: line }))
diff --git a/src/libreader/parser.rs b/src/libreader/parser.rs
index b79ff16cc3..0c573558c7 100644
--- a/src/libreader/parser.rs
+++ b/src/libreader/parser.rs
@@ -11,11 +11,11 @@ use std::fmt::{self, Display, Formatter};
 use std::str::FromStr;
 use std::u32;
 use lexer::{self, Lexer, Token};
-use cretonne::types::{Type, VOID, FunctionName, Signature, ArgumentType, ArgumentExtension};
-use cretonne::immediates::{Imm64, Ieee32, Ieee64};
-use cretonne::entities::*;
-use cretonne::instructions::{Opcode, InstructionFormat, InstructionData, VariableArgs, JumpData,
-                             BranchData, ReturnData};
+use cretonne::repr::types::{Type, VOID, FunctionName, Signature, ArgumentType, ArgumentExtension};
+use cretonne::repr::immediates::{Imm64, Ieee32, Ieee64};
+use cretonne::repr::entities::*;
+use cretonne::repr::instructions::{Opcode, InstructionFormat, InstructionData, VariableArgs,
+                                   JumpData, BranchData, ReturnData};
 use cretonne::repr::{Function, StackSlotData};
 
 pub use lexer::Location;
@@ -1039,7 +1039,7 @@ impl<'a> Parser<'a> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use cretonne::types::{self, ArgumentType, ArgumentExtension};
+    use cretonne::repr::types::{self, ArgumentType, ArgumentExtension};
 
     #[test]
     fn argument_type() {
diff --git a/src/tools/print_cfg.rs b/src/tools/print_cfg.rs
index 1c7f0e7a19..155de0e4a1 100644
--- a/src/tools/print_cfg.rs
+++ b/src/tools/print_cfg.rs
@@ -8,7 +8,7 @@ use std::io::{Read, Write, stdout};
 use CommandResult;
 use cretonne::repr::Function;
 use cretonne::cfg::ControlFlowGraph;
-use cretonne::instructions::InstructionData;
+use cretonne::repr::instructions::InstructionData;
 use cton_reader::parser::Parser;
 
 pub fn run(files: Vec<String>) -> CommandResult {