diff --git a/Cargo.lock b/Cargo.lock
index 501ee450dd..b85693f316 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5476,6 +5476,10 @@ dependencies = [
  "url",
 ]
 
+[[package]]
+name = "penumbra-mock-cometbft"
+version = "0.64.1"
+
 [[package]]
 name = "penumbra-num"
 version = "0.64.1"
diff --git a/Cargo.toml b/Cargo.toml
index e6ac21c3c2..a9898c9971 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,6 +44,7 @@ members = [
   "crates/bin/pcli",
   "crates/wasm",
   "crates/test/tct-property-test",
+  "crates/test/mock-cometbft",
   "crates/misc/measure",
   "crates/misc/tct-visualize",
   "crates/bench",
diff --git a/crates/test/mock-cometbft/Cargo.toml b/crates/test/mock-cometbft/Cargo.toml
new file mode 100644
index 0000000000..34aea8b30d
--- /dev/null
+++ b/crates/test/mock-cometbft/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "penumbra-mock-cometbft"
+version = "0.64.1"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/crates/test/mock-cometbft/src/lib.rs b/crates/test/mock-cometbft/src/lib.rs
new file mode 100644
index 0000000000..7d12d9af81
--- /dev/null
+++ b/crates/test/mock-cometbft/src/lib.rs
@@ -0,0 +1,14 @@
+pub fn add(left: usize, right: usize) -> usize {
+    left + right
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let result = add(2, 2);
+        assert_eq!(result, 4);
+    }
+}