diff --git a/src/libcretonne/isa/mod.rs b/src/libcretonne/isa/mod.rs
new file mode 100644
index 0000000000..e2f48e7bbe
--- /dev/null
+++ b/src/libcretonne/isa/mod.rs
@@ -0,0 +1,6 @@
+//! Instruction Set Architectures.
+//!
+//! The sub-modules of this `isa` module provide definitions for the instruction sets that Cretonne
+//! can target.
+
+pub mod riscv;
diff --git a/src/libcretonne/isa/riscv/mod.rs b/src/libcretonne/isa/riscv/mod.rs
new file mode 100644
index 0000000000..4c24cbb8b7
--- /dev/null
+++ b/src/libcretonne/isa/riscv/mod.rs
@@ -0,0 +1 @@
+//! RISC-V Instruction Set Architecture.
diff --git a/src/libcretonne/lib.rs b/src/libcretonne/lib.rs
index 34151d187b..9d696fab53 100644
--- a/src/libcretonne/lib.rs
+++ b/src/libcretonne/lib.rs
@@ -8,6 +8,7 @@
 pub const VERSION: &'static str = env!("CARGO_PKG_VERSION");
 
 pub mod ir;
+pub mod isa;
 pub mod write;
 pub mod cfg;
 pub mod dominator_tree;