diff --git a/denoiser.hpp b/denoiser.hpp
index 7a8242e7d..00bad2ec7 100644
--- a/denoiser.hpp
+++ b/denoiser.hpp
@@ -276,6 +276,10 @@ struct KarrasScheduler : SigmaScheduler {
         // but does anybody ever bother to touch them?
         float rho = 7.f;
 
+        if (sigma_min <= 1e-6f) {
+            sigma_min = 1e-6f;
+        }
+
         std::vector<float> result(n + 1);
 
         float min_inv_rho = pow(sigma_min, (1.f / rho));
@@ -347,7 +351,11 @@ struct SmoothStepScheduler : SigmaScheduler {
     }
 };
 
-// Implementation adapted from https://github.com/AUTOMATIC1111/stable-diffusion-webui/pull/15608
+/*
+* KL Optimal:
+*     Original work from https://github.com/AUTOMATIC1111/stable-diffusion-webui/pull/15608.
+*     Implemented using https://github.com/comfyanonymous/ComfyUI/pull/6206 as a reference.
+*/
 struct KLOptimalScheduler : SigmaScheduler {
     std::vector<float> get_sigmas(uint32_t n, float sigma_min, float sigma_max, t_to_sigma_t t_to_sigma) override {
         std::vector<float> sigmas;
@@ -355,27 +363,29 @@ struct KLOptimalScheduler : SigmaScheduler {
         if (n == 0) {
             return sigmas;
         }
+
         if (n == 1) {
             sigmas.push_back(sigma_max);
             sigmas.push_back(0.0f);
             return sigmas;
         }
 
+        if (sigma_min <= 1e-6f) {
+            sigma_min = 1e-6f;
+        }
+
+        sigmas.reserve(n + 1);
+
         float alpha_min = std::atan(sigma_min);
         float alpha_max = std::atan(sigma_max);
 
         for (uint32_t i = 0; i < n; ++i) {
-            // t goes from 0.0 to 1.0
-            float t = static_cast<float>(i) / static_cast<float>(n - 1);
 
-            // Interpolate in the angle domain
+            float t = static_cast<float>(i) / static_cast<float>(n - 1);
             float angle = t * alpha_min + (1.0f - t) * alpha_max;
-
-            // Convert back to sigma
             sigmas.push_back(std::tan(angle));
         }
 
-        // Append the final zero to sigma
         sigmas.push_back(0.0f);
 
         return sigmas;