diff --git a/cmdapp/Cargo.toml b/cmdapp/Cargo.toml
index 13252d6..e5fe2d5 100644
--- a/cmdapp/Cargo.toml
+++ b/cmdapp/Cargo.toml
@@ -14,7 +14,7 @@ keywords = ["svg", "computer-graphics"]
 clap = "2.33.3"
 image = "0.23.10"
 visioncortex = { version = "0.8.8" }
-fastrand = "1.8"
+fastrand = { version = "2.3", features = ["js"] }
 pyo3 = { version = "0.19.0", optional = true }
 
 [features]
diff --git a/cmdapp/src/converter.rs b/cmdapp/src/converter.rs
index cfa4fa5..448b5cd 100644
--- a/cmdapp/src/converter.rs
+++ b/cmdapp/src/converter.rs
@@ -53,7 +53,7 @@ fn find_unused_color_in_image(img: &ColorImage) -> Result<Color, String> {
         Color::new(0, 255, 255),
         Color::new(255, 0, 255),
     ]);
-    let rng = Rng::new();
+    let mut rng = Rng::new();
     let random_colors =
         (0..NUM_UNUSED_COLOR_ITERATIONS).map(|_| Color::new(rng.u8(..), rng.u8(..), rng.u8(..)));
     for color in special_colors.chain(random_colors) {