diff --git a/include/mcc/mcc_pcm_fit.h b/include/mcc/mcc_pcm_fit.h
index 499c276..5f96149 100644
--- a/include/mcc/mcc_pcm_fit.h
+++ b/include/mcc/mcc_pcm_fit.h
@@ -394,7 +394,7 @@ protected:
         // full knot vectors: [t_min, t_min, t_min, t_min, ..., t_1, t_2, ..., t_max, t_max, t_max, t_max]
         std::vector<double> tx(pcm_data.bspline.knotsX.size() + 6), ty(pcm_data.bspline.knotsY.size() + 6);
 
-        std::vector<double>&theta_hw = _hwY, &theta_tag = _targetCOLAT, &phi_hw = _hwX, &phi_tag = _targetCOLON;
+        std::vector<double>*theta_hw = &_hwY, *theta_tag = &_targetCOLAT, *phi_hw = &_hwX, *phi_tag = &_targetCOLON;
         std::vector<double> theta, phi;
 
         // full set of B-spline knots
@@ -432,8 +432,8 @@ protected:
                 theta[i] = _hwY[i] + MCC_HALF_PI;
                 phi[i] = _hwX[i] + std::numbers::pi;
             }
-            theta_hw = theta;
-            phi_hw = phi;
+            theta_hw = &theta;
+            phi_hw = &phi;
 
             for (size_t i = 0; i < tx.size(); ++i) {
                 tx[i] += std::numbers::pi;
@@ -452,24 +452,24 @@ protected:
 
         // direct (celestial = encoder + pcm)
         result.bspline_fit_err[0] =
-            bsplines::fitpack_sphere_fit(theta_hw, phi_hw, _colonRES, 1.0, ty, tx, pcm_data.bspline.coeffsX, resi2x);
+            bsplines::fitpack_sphere_fit(*theta_hw, *phi_hw, _colonRES, 1.0, ty, tx, pcm_data.bspline.coeffsX, resi2x);
         if (result.bspline_fit_err[0] > 0) {
             result.error = MccPCMFitterErrorCode::ERROR_BSPLINE_FIT;
             return result;
         }
 
         result.bspline_fit_err[1] =
-            bsplines::fitpack_sphere_fit(theta_hw, phi_hw, _colatRES, 1.0, ty, tx, pcm_data.bspline.coeffsY, resi2y);
+            bsplines::fitpack_sphere_fit(*theta_hw, *phi_hw, _colatRES, 1.0, ty, tx, pcm_data.bspline.coeffsY, resi2y);
         if (result.bspline_fit_err[1] > 0) {
             result.error = MccPCMFitterErrorCode::ERROR_BSPLINE_FIT;
             return result;
         }
 
 
-        bsplines::fitpack_eval_spl2d(ty, tx, pcm_data.bspline.coeffsX, theta_hw, phi_hw,
+        bsplines::fitpack_eval_spl2d(ty, tx, pcm_data.bspline.coeffsX, *theta_hw, *phi_hw,
                                      result.model_colonRES);  // get fitted residuals!!!
 
-        bsplines::fitpack_eval_spl2d(ty, tx, pcm_data.bspline.coeffsY, theta_hw, phi_hw,
+        bsplines::fitpack_eval_spl2d(ty, tx, pcm_data.bspline.coeffsY, *theta_hw, *phi_hw,
                                      result.model_colatRES);  // get fitted residuals!!!
 
         result.colon_err.resize(numberOfPoints());
@@ -488,8 +488,8 @@ protected:
             // inverse (encoder = celestial + pcm)
 
             if constexpr (std::same_as<ref_coordpair_t, MccSkyHADEC_OBS>) {
-                theta_tag = theta;
-                phi_tag = phi;
+                theta_tag = &theta;
+                phi_tag = &phi;
             }
 
             std::vector<double> colon_res = _colonRES;
@@ -499,29 +499,29 @@ protected:
                 colat_res[i] = -colat_res[i];
 
                 if constexpr (std::same_as<ref_coordpair_t, MccSkyHADEC_OBS>) {
-                    theta_tag[i] = _targetCOLAT[i] + MCC_HALF_PI;
-                    phi_tag[i] = _targetCOLON[i] + std::numbers::pi;
+                    (*theta_tag)[i] = _targetCOLAT[i] + MCC_HALF_PI;
+                    (*phi_tag)[i] = _targetCOLON[i] + std::numbers::pi;
                 }
             }
 
-            result.bspline_fit_err[2] = bsplines::fitpack_sphere_fit(theta_tag, phi_tag, colon_res, 1.0, ty, tx,
+            result.bspline_fit_err[2] = bsplines::fitpack_sphere_fit(*theta_tag, *phi_tag, colon_res, 1.0, ty, tx,
                                                                      pcm_data.bspline.inverseCoeffsX, resi2x);
             if (result.bspline_fit_err[2] > 0) {
                 result.error = MccPCMFitterErrorCode::ERROR_BSPLINE_FIT;
                 return result;
             }
 
-            result.bspline_fit_err[3] = bsplines::fitpack_sphere_fit(theta_tag, phi_tag, colat_res, 1.0, ty, tx,
+            result.bspline_fit_err[3] = bsplines::fitpack_sphere_fit(*theta_tag, *phi_tag, colat_res, 1.0, ty, tx,
                                                                      pcm_data.bspline.inverseCoeffsY, resi2y);
             if (result.bspline_fit_err[3] > 0) {
                 result.error = MccPCMFitterErrorCode::ERROR_BSPLINE_FIT;
                 return result;
             }
 
-            bsplines::fitpack_eval_spl2d(ty, tx, pcm_data.bspline.inverseCoeffsX, theta_tag, phi_tag,
+            bsplines::fitpack_eval_spl2d(ty, tx, pcm_data.bspline.inverseCoeffsX, *theta_tag, *phi_tag,
                                          result.inv_model_colonRES);  // get fitted residuals!!!
 
-            bsplines::fitpack_eval_spl2d(ty, tx, pcm_data.bspline.inverseCoeffsY, theta_tag, phi_tag,
+            bsplines::fitpack_eval_spl2d(ty, tx, pcm_data.bspline.inverseCoeffsY, *theta_tag, *phi_tag,
                                          result.inv_model_colatRES);  // get fitted residuals!!!
 
             result.inv_colon_err.resize(numberOfPoints());
diff --git a/tests/mcc_pcm_z1000_test.cpp b/tests/mcc_pcm_z1000_test.cpp
index c66cd2c..f63e046 100644
--- a/tests/mcc_pcm_z1000_test.cpp
+++ b/tests/mcc_pcm_z1000_test.cpp
@@ -138,7 +138,7 @@ int main(int narg, char* argv[])
 
     fit_pcm_data.type = MccDefaultPCMType::PCM_TYPE_BSPLINE;
 
-    r = pcm_cstr.computeModel(fit_pcm_data);
+    // r = pcm_cstr.computeModel(fit_pcm_data);
     fr = pcm_fitter.computeModel(fit_pcm_data);
 
     // if (r.error) {
@@ -150,6 +150,8 @@ int main(int narg, char* argv[])
         std::println("error: {}", fr.error.message());
         std::println("b-spline error: {}", fr.bspline_fit_err);
         return 1;
+    } else {
+        std::println("b-spline fit exit code: {}", fr.bspline_fit_err);
     }
 
     std::println("\n\n{:*^40}\n", " FITTED DIFFS ");