diff --git a/.cargo/config.toml b/.cargo/config.toml
new file mode 100644
index 00000000..758ed610
--- /dev/null
+++ b/.cargo/config.toml
@@ -0,0 +1,2 @@
+[target.wasm32-unknown-unknown]
+runner = "wasm-server-runner"
diff --git a/Cargo.toml b/Cargo.toml
index 627d8ad0..99174d33 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,6 @@ edition = "2024"
 
 [dependencies]
 bevy = "0.16.0"
-bevy_spatial = "0.11.0"
 
 # Grand-dependency pins
 ab_glyph = "0.2.16"
@@ -17,6 +16,16 @@ miniz-sys = "0.1.10"
 nonmax = "0.5.1"
 rand = "0.8.0"
 
+# Use regular bevy_spatial on non-WASM builds
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+bevy_spatial = "0.11.0"
+
+# Use bevy_spatial *without* the kdtree_rayon feature when building for WASM.
+[target.'cfg(target_arch = "wasm32")'.dependencies.bevy_spatial]
+version = "0.11.0"
+default-features = false
+features = ["kdtree"]
+
 [profile.dev]
 opt-level = 1