diff --git a/codecs/visdif/Cargo.lock b/codecs/visdif/Cargo.lock
index b3d4397f..65e52f7c 100644
--- a/codecs/visdif/Cargo.lock
+++ b/codecs/visdif/Cargo.lock
@@ -85,8 +85,6 @@ dependencies = [
 [[package]]
 name = "dssim-core"
 version = "2.11.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "462c6cf1cb98d8f7dc5f7a5878e9f05e6be51086370f7f162e446a62ebfab0cb"
 dependencies = [
  "imgref",
  "itertools",
@@ -281,7 +279,6 @@ dependencies = [
  "console_error_panic_hook",
  "dssim-core",
  "imgref",
- "rayon-core",
  "rgb",
  "wasm-bindgen",
  "wasm-bindgen-test",
diff --git a/codecs/visdif/Cargo.toml b/codecs/visdif/Cargo.toml
index 1e4ec765..6814f128 100644
--- a/codecs/visdif/Cargo.toml
+++ b/codecs/visdif/Cargo.toml
@@ -15,10 +15,11 @@ default = ["console_error_panic_hook", "wee_alloc"]
 [dependencies]
 cfg-if = "0.1.2"
 wasm-bindgen = "0.2.38"
-dssim-core = "2.11.3"
 imgref = "1.7.0"
 rgb = "0.8.24"
-rayon-core = "1.7.1"
+#rayon-core = "1.7.1"
+
+
 # The `console_error_panic_hook` crate provides better debugging of panics by
 # logging them with `console.error`. This is great for development, but requires
 # all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
@@ -32,10 +33,10 @@ console_error_panic_hook = { version = "0.1.1", optional = true }
 # Unfortunately, `wee_alloc` requires nightly Rust when targeting wasm for now.
 wee_alloc = { version = "0.4.2", optional = true }
 
-#[dependencies.dssim]
-#path = "/Users/surma/src/github.com/kornelski/dssim"
-
-#dssim = "2.11.2"
+[dependencies.dssim-core]
+path = "/Users/surma/src/github.com/kornelski/dssim/dssim-core"
+# Shim rayon API
+default-features = false
 
 [dev-dependencies]
 wasm-bindgen-test = "0.2"
diff --git a/codecs/visdif/src/lib.rs b/codecs/visdif/src/lib.rs
index b35be307..a482adde 100644
--- a/codecs/visdif/src/lib.rs
+++ b/codecs/visdif/src/lib.rs
@@ -4,7 +4,7 @@ use wasm_bindgen::prelude::*;
 use dssim_core::{Dssim, ToRGBAPLU};
 use imgref;
 use rgb::FromSlice;
-use rayon_core;
+//use rayon_core;
 
 mod utils;