diff --git a/pyFAI/resources/openCL/ocl_azim_CSR.cl b/pyFAI/resources/openCL/ocl_azim_CSR.cl
index 01fdb430..d5483bc7 100644
--- a/pyFAI/resources/openCL/ocl_azim_CSR.cl
+++ b/pyFAI/resources/openCL/ocl_azim_CSR.cl
@@ -103,7 +103,7 @@ csr_integrate(  const   global  float   *weights,
                    //Kahan summation allows single precision arithmetics with error compensation
                    //http://en.wikipedia.org/wiki/Kahan_summation_algorithm
                    // defined in kahan.cl
-                   sum_data_K = kahan_sum(sum_data_K, pown(coef, coef_power) * data);
+                   sum_data_K = kahan_sum(sum_data_K, ((coef_power == 2) ? coef*coef: coef) * data);
                    sum_count_K = kahan_sum(sum_count_K, coef);
                };//end if dummy
        } //end if k < bin_bounds.y
diff --git a/pyFAI/resources/openCL/ocl_azim_LUT.cl b/pyFAI/resources/openCL/ocl_azim_LUT.cl
index 161156bc..4ebd86c4 100644
--- a/pyFAI/resources/openCL/ocl_azim_LUT.cl
+++ b/pyFAI/resources/openCL/ocl_azim_LUT.cl
@@ -114,7 +114,7 @@ lut_integrate(  const     global    float              *weights,
                 //sum_count += coef;
                 //Kahan summation allows single precision arithmetics with error compensation
                 //http://en.wikipedia.org/wiki/Kahan_summation_algorithm
-                sum_data_K = kahan_sum(sum_data_K, pown(coef, coef_power) * data);
+                sum_data_K = kahan_sum(sum_data_K, ((coef_power == 2) ? coef*coef: coef) * data);
                 sum_count_K = kahan_sum(sum_count_K, coef);
             };//end if dummy
         };//for j