diff --git a/intern/cycles/kernel/film/read.h b/intern/cycles/kernel/film/read.h
index 108f992e29d..6c29b79b29b 100644
--- a/intern/cycles/kernel/film/read.h
+++ b/intern/cycles/kernel/film/read.h
@@ -485,11 +485,19 @@ ccl_device_inline float4 film_calculate_shadow_catcher_matte_with_shadow(

   if (kfilm_convert->use_approximate_shadow_catcher_background) {
     kernel_assert(kfilm_convert->pass_background != PASS_UNUSED);
+    kernel_assert(kfilm_convert->pass_shadow_catcher_sample_count != PASS_UNUSED);
+
+    ccl_global const float *in_catcher_sample_count =
+        buffer + kfilm_convert->pass_shadow_catcher_sample_count;
+    const float num_samples = in_catcher_sample_count[0];
+    const float background_scale_exposure = (num_samples != 0.0f) ?
+                                                (1.0f / num_samples * kfilm_convert->exposure) :
+                                                scale_exposure;

     ccl_global const float *in_background = buffer + kfilm_convert->pass_background;
     const float3 color_background = make_float3(
                                         in_background[0], in_background[1], in_background[2]) *
-                                    scale_exposure;
+                                    background_scale_exposure;
     const float3 alpha_over = color_matte + color_background * (1.0f - alpha_matte);
     return make_float4(alpha_over.x, alpha_over.y, alpha_over.z, 1.0f);
   }