diff --git a/js/pathfinding.js b/js/pathfinding.js
index 6947e0c..43a5521 100644
--- a/js/pathfinding.js
+++ b/js/pathfinding.js
@@ -80,7 +80,18 @@ class Cache {
 	 */
 	getCacheLayer(token) {
 		const tokenData = buildTokenData(token);
-		const cacheId = JSON.stringify(tokenData);
+		// TODO Request this from the speed providers so they can set their own options
+		let terrainData = canvas.terrain.listTerrain({token});
+		terrainData = terrainData.map(data => {
+			return {
+				x: data.object.x,
+				y: data.object.y,
+				cost: data.cost,
+				shape: data.shape,
+			};
+		});
+		const cacheIdData = {tokenData, terrainData};
+		const cacheId = GridlessPathfinding.sha1(JSON.stringify(cacheIdData));
 		let cacheLayer = this.layers.get(cacheId);
 		// If we don't already have a cache layer for this cache ID, create one now
 		if (!cacheLayer) {
diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index c0676ea..1a86120 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "block-buffer"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0bf7fe51849ea569fd452f37822f606a5cabb684dc918707a0193fd4664ff324"
+dependencies = [
+ "generic-array",
+]
+
 [[package]]
 name = "bumpalo"
 version = "3.9.1"
@@ -24,6 +33,45 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "cpufeatures"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59a6001667ab124aebae2a495118e11d30984c3a653e99d86d58971708cf5e4b"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "crypto-common"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57952ca27b5e3606ff4dd79b0020231aaf9d6aa76dc05fd30137538c50bd3ce8"
+dependencies = [
+ "generic-array",
+ "typenum",
+]
+
+[[package]]
+name = "digest"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2fb860ca6fafa5552fb6d0e816a69c8e49f0908bf524e30a90d97c85892d506"
+dependencies = [
+ "block-buffer",
+ "crypto-common",
+]
+
+[[package]]
+name = "generic-array"
+version = "0.14.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd48d33ec7f05fbfa152300fdad764757cbded343c1aa1cff2fbaf4134851803"
+dependencies = [
+ "typenum",
+ "version_check",
+]
+
 [[package]]
 name = "gridless-pathfinding"
 version = "1.12.8"
@@ -31,6 +79,7 @@ dependencies = [
  "console_error_panic_hook",
  "js-sys",
  "rustc-hash",
+ "sha1",
  "wasm-bindgen",
 ]
 
@@ -49,6 +98,12 @@ version = "1.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
+[[package]]
+name = "libc"
+version = "0.2.125"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5916d2ae698f6de9bfb891ad7a8d65c09d232dc58cc4ac433c7da3b2fd84bc2b"
+
 [[package]]
 name = "log"
 version = "0.4.14"
@@ -82,6 +137,17 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
+[[package]]
+name = "sha1"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c77f4e7f65455545c2153c1253d25056825e77ee2533f0e41deb65a93a34852f"
+dependencies = [
+ "cfg-if",
+ "cpufeatures",
+ "digest",
+]
+
 [[package]]
 name = "syn"
 version = "1.0.86"
@@ -93,12 +159,24 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "typenum"
+version = "1.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcf81ac59edc17cc8697ff311e8f5ef2d99fcbd9817b34cec66f90b6c3dfd987"
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
 
+[[package]]
+name = "version_check"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
+
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.79"
diff --git a/rust/Cargo.toml b/rust/Cargo.toml
index 226a9b6..02b8521 100644
--- a/rust/Cargo.toml
+++ b/rust/Cargo.toml
@@ -16,4 +16,5 @@ lto = true
 console_error_panic_hook = "0.1.7"
 js-sys = "0.3.56"
 rustc-hash = "1.1.0"
+sha1 = "0.10.1"
 wasm-bindgen = "0.2.79"
diff --git a/rust/src/js_api.rs b/rust/src/js_api.rs
index c90a532..d2fbc8c 100644
--- a/rust/src/js_api.rs
+++ b/rust/src/js_api.rs
@@ -1,4 +1,5 @@
 use js_sys::Array;
+use sha1::{Sha1, Digest};
 use wasm_bindgen::prelude::*;
 
 use crate::{
@@ -262,6 +263,14 @@ pub fn debug_get_pathfinding_points(pathfinder: &Pathfinder) -> Array {
 		.collect()
 }
 
+#[allow(dead_code)]
+#[wasm_bindgen]
+pub fn sha1(input: &str) -> String {
+	let mut hasher = Sha1::new();
+	hasher.update(input);
+	format!("{:x}", hasher.finalize())
+}
+
 trait IteratePath {
 	fn iter_path(&self) -> PathIterator;
 }