diff --git a/image_analysis/bragg_prediction/BraggPredictionRotGPU.cu b/image_analysis/bragg_prediction/BraggPredictionRotGPU.cu
index 46968ddf..5a0ed52e 100644
--- a/image_analysis/bragg_prediction/BraggPredictionRotGPU.cu
+++ b/image_analysis/bragg_prediction/BraggPredictionRotGPU.cu
@@ -286,7 +286,8 @@ int BraggPredictionRotGPU::Calc(const DiffractionExperiment &experiment,
     cudaMemcpyAsync(dK, &hK, sizeof(KernelConstsRot), cudaMemcpyHostToDevice, stream);
     cudaMemsetAsync(d_count, 0, sizeof(int), stream);
 
-    const int range = 2 * settings.max_hkl;
+    // Inclusive on both ends, matching the kernel's own range and the CPU loop (-max_hkl .. +max_hkl).
+    const int range = 2 * settings.max_hkl + 1;
     dim3 block(8, 8, 8);
     dim3 grid((range + block.x - 1) / block.x,
               (range + block.y - 1) / block.y,