diff --git a/singularity-opac/neutrinos/mean_opacity_neutrinos.hpp b/singularity-opac/neutrinos/mean_opacity_neutrinos.hpp
index fa2aa1f..bfb15b5 100644
--- a/singularity-opac/neutrinos/mean_opacity_neutrinos.hpp
+++ b/singularity-opac/neutrinos/mean_opacity_neutrinos.hpp
@@ -141,7 +141,7 @@ class MeanOpacity {
                         const Real YeMax, const int NYe, Real lNuMin,
                         Real lNuMax, const int NNu, Real *lambda = nullptr) {
 #ifndef NDEBUG
-    auto RPC = RuntimePhysicalConstants(PC);
+    auto RPC = RuntimePhysicalConstants(PC());
     auto opc = opac.GetRuntimePhysicalConstants();
     assert(RPC == opc && "Physical constants are the same");
 #endif
diff --git a/singularity-opac/photons/mean_opacity_photons.hpp b/singularity-opac/photons/mean_opacity_photons.hpp
index e00e61b..e9bdd02 100644
--- a/singularity-opac/photons/mean_opacity_photons.hpp
+++ b/singularity-opac/photons/mean_opacity_photons.hpp
@@ -150,7 +150,7 @@ class MeanOpacity {
                         const Real lTMax, const int NT, Real lNuMin,
                         Real lNuMax, const int NNu, Real *lambda = nullptr) {
 #ifndef NDEBUG
-    auto RPC = RuntimePhysicalConstants(PC);
+    auto RPC = RuntimePhysicalConstants(PC());
     auto opc = opac.GetRuntimePhysicalConstants();
     assert(RPC == opc && "Physical constants are the same");
 #endif