diff --git a/include/mcc/mcc_pcm.h b/include/mcc/mcc_pcm.h
index a13606c..822e3bb 100644
--- a/include/mcc/mcc_pcm.h
+++ b/include/mcc/mcc_pcm.h
@@ -387,7 +387,7 @@ public:
                     MccCoordPair<typename T::x_t, typename T::y_t>{x + res->pcmX, y + res->pcmY, obs_skycoord.epoch()};
             }
         } else {  // for B-splines the result is computed directly from inverse B-spline coefficients
-            ret = _computeFuncDeriv(x, y, res);
+            ret = _computeFuncDeriv(x, y, res, true);
 
             if (!ret) {
                 if constexpr (mcc_coord_pair_c<T>) {
diff --git a/include/mcc/mcc_pcm_fit.h b/include/mcc/mcc_pcm_fit.h
index 5f96149..d795f70 100644
--- a/include/mcc/mcc_pcm_fit.h
+++ b/include/mcc/mcc_pcm_fit.h
@@ -355,29 +355,30 @@ protected:
     std::vector<MccCelestialCoordEpoch> _epoch{};
 
 
-    void computeModelResi(compute_result_t& result)
-    {
-        result.colon_err.resize(numberOfPoints());
-        result.colat_err.resize(numberOfPoints());
+    //     void computeModelResi(compute_result_t& result)
+    //     {
+    //         result.colon_err.resize(numberOfPoints());
+    //         result.colat_err.resize(numberOfPoints());
+
+    //         for (size_t i = 0; i < numberOfPoints(); ++i) {
+    //             result.colon_err[i] = _colonRES[i] - result.model_colonRES[i];  // = target - model
+    //             result.colat_err[i] = _colatRES[i] - result.model_colatRES[i];  // = target - model
+    //         }
+
+    // #ifdef USE_BSPLINE_PCM
+    //         if (result.pcm_type == MccDefaultPCMType::PCM_TYPE_BSPLINE) {
+    //             result.inv_colon_err.resize(numberOfPoints());
+    //             result.inv_colat_err.resize(numberOfPoints());
+    //             for (size_t i = 0; i < numberOfPoints(); ++i) {
+    //                 result.inv_colon_err[i] = _colonRES[i] - result.inv_model_colonRES[i];  // = hw - model
+    //                 result.inv_colat_err[i] = _colatRES[i] - result.inv_model_colatRES[i];  // = hw - model
+    //             }
+    //         }
+    // #endif
+    //     }
 
-        for (size_t i = 0; i < numberOfPoints(); ++i) {
-            result.colon_err[i] = _colonRES[i] - result.model_colonRES[i];  // = target - model
-            result.colat_err[i] = _colatRES[i] - result.model_colatRES[i];  // = target - model
-        }
 
 #ifdef USE_BSPLINE_PCM
-        if (result.pcm_type == MccDefaultPCMType::PCM_TYPE_BSPLINE) {
-            result.inv_colon_err.resize(numberOfPoints());
-            result.inv_colat_err.resize(numberOfPoints());
-            for (size_t i = 0; i < numberOfPoints(); ++i) {
-                result.inv_colon_err[i] = _colonRES[i] - result.inv_model_colonRES[i];  // = hw - model
-                result.inv_colat_err[i] = _colatRES[i] - result.inv_model_colatRES[i];  // = hw - model
-            }
-        }
-#endif
-    }
-
-
     compute_result_t bsplineFitting(MccDefaultPCM<MOUNT_TYPE>::pcm_data_t& pcm_data)
     {
         compute_result_t result{.pcm_type = pcm_data.type, .error = MccPCMFitterErrorCode::ERROR_OK};
@@ -534,6 +535,7 @@ protected:
 
         return result;
     }
+#endif
 
 
     compute_result_t robustLinearRegress(MccDefaultPCM<MOUNT_TYPE>::pcm_data_t& pcm_data,