diff --git a/dfdx-core/src/tensor_ops/prodigy/cpu_kernel.rs b/dfdx-core/src/tensor_ops/prodigy/cpu_kernel.rs
index 6cc2d6be..f6789b38 100644
--- a/dfdx-core/src/tensor_ops/prodigy/cpu_kernel.rs
+++ b/dfdx-core/src/tensor_ops/prodigy/cpu_kernel.rs
@@ -152,7 +152,13 @@ impl<E: num_traits::Float + Dtype + NotMixedPrecision> ProdigyKernel<E> for Cpu
     ) -> Result<(), Error> {
         let mut d_denom_: E = E::zero();
         let [beta1, beta2] = cfg.betas.map(E::from_f64).map(Option::unwrap);
-        let beta3 = E::from_f64(cfg.beta3.unwrap_or_else(|| cfg.betas[1].sqrt())).unwrap();
+        let beta3 = E::from_f64(cfg.beta3.unwrap_or_else(|| {
+            #[cfg(feature = "no-std")]
+            use num_traits::Float;
+
+            cfg.betas[1].sqrt()
+        }))
+        .unwrap();
 
         let bias_correction = if cfg.use_bias_correction {
             // note: in here the first k = 1, whereas on the reference python code it's 0
diff --git a/dfdx/src/nn/optim/prodigy.rs b/dfdx/src/nn/optim/prodigy.rs
index dfe80f0c..5e80947c 100644
--- a/dfdx/src/nn/optim/prodigy.rs
+++ b/dfdx/src/nn/optim/prodigy.rs
@@ -166,12 +166,27 @@ mod tests {
             .zip(expected_updates)
         {
             let prediction = m.forward_mut(x.trace(grads));
+
+            #[cfg(feature = "test-f64")]
+            assert_close_to_literal!(prediction, ey, 7e-5);
+            #[cfg(not(feature = "test-f64"))]
             assert_close_to_literal!(prediction, ey);
+
             let loss = crate::losses::mse_loss(prediction, dev.tensor(y));
             grads = loss.backward();
+
+            #[cfg(feature = "test-f64")]
+            assert_close_to_literal!(grads.get(&m.weight), eg, 3e-5);
+            #[cfg(not(feature = "test-f64"))]
             assert_close_to_literal!(grads.get(&m.weight), eg);
+
             opt.update(&mut m, &grads).expect("");
+
+            #[cfg(feature = "test-f64")]
+            assert_close_to_literal!(m.weight, eu, 5e-4);
+            #[cfg(not(feature = "test-f64"))]
             assert_close_to_literal!(m.weight, eu);
+
             m.zero_grads(&mut grads);
         }
     }