diff --git a/src/include/gridfire/reaction/reaction.h b/src/include/gridfire/reaction/reaction.h
index 595ae17c..ca082ed4 100644
--- a/src/include/gridfire/reaction/reaction.h
+++ b/src/include/gridfire/reaction/reaction.h
@@ -888,12 +888,13 @@ namespace gridfire::reaction {
 
         friend std::ostream& operator<<(std::ostream& os, const ReactionSet& rs) {
             os << "(ReactionSet: {";
-            int i = 0;
+            size_t i = 0;
             for (const auto& reaction : rs.m_reactions) {
                 os << *reaction;
                 if (i < rs.m_reactions.size() - 1) {
                     os << ", ";
                 }
+                ++i;
             }
             os << "})";
             return os;
diff --git a/src/lib/engine/procedures/construction.cpp b/src/lib/engine/procedures/construction.cpp
index e3d0cb31..a46cf969 100644
--- a/src/lib/engine/procedures/construction.cpp
+++ b/src/lib/engine/procedures/construction.cpp
@@ -256,4 +256,4 @@ namespace gridfire {
     }
 
 
-}
\ No newline at end of file
+}
diff --git a/src/lib/engine/views/engine_multiscale.cpp b/src/lib/engine/views/engine_multiscale.cpp
index 350e3c2e..e5c65b9a 100644
--- a/src/lib/engine/views/engine_multiscale.cpp
+++ b/src/lib/engine/views/engine_multiscale.cpp
@@ -1293,7 +1293,7 @@ namespace gridfire {
             if (status <= 0 || status >= 4) {
                 std::stringstream msg;
                 msg << "While working on QSE group with algebraic species: ";
-                int count = 0;
+                size_t count = 0;
                 for (const auto& species: algebraic_species) {
                     msg << species;
                     if (count < algebraic_species.size() - 1) {
diff --git a/src/lib/screening/screening_types.cpp b/src/lib/screening/screening_types.cpp
index dac79ecf..4d489ced 100644
--- a/src/lib/screening/screening_types.cpp
+++ b/src/lib/screening/screening_types.cpp
@@ -7,11 +7,12 @@
 
 namespace gridfire::screening {
     std::unique_ptr<ScreeningModel> selectScreeningModel(const ScreeningType type) {
-        switch (type) {
-            case ScreeningType::WEAK:
-                return std::make_unique<WeakScreeningModel>();
-            case ScreeningType::BARE:
-                return std::make_unique<BareScreeningModel>();
-        }
+      switch (type) {
+          case ScreeningType::WEAK:
+              return std::make_unique<WeakScreeningModel>();
+          case ScreeningType::BARE:
+              return std::make_unique<BareScreeningModel>();
+      }
+      throw std::runtime_error("Unknown ScreeningType");
     }
 }
diff --git a/src/lib/solver/strategies/CVODE_solver_strategy.cpp b/src/lib/solver/strategies/CVODE_solver_strategy.cpp
index 105ffd3b..42c4c57b 100644
--- a/src/lib/solver/strategies/CVODE_solver_strategy.cpp
+++ b/src/lib/solver/strategies/CVODE_solver_strategy.cpp
@@ -249,7 +249,7 @@ namespace gridfire::solver {
 
                 fourdst::composition::Composition temp_comp;
                 std::vector<double> mass_fractions;
-                size_t num_species_at_stop = m_engine.getNetworkSpecies().size();
+                long int num_species_at_stop = m_engine.getNetworkSpecies().size();
 
                 if (num_species_at_stop > m_Y->ops->nvgetlength(m_Y) - 1) {
                     LOG_ERROR(
@@ -263,7 +263,7 @@ namespace gridfire::solver {
 
                 mass_fractions.reserve(num_species_at_stop);
 
-                for (size_t i = 0; i < num_species_at_stop; ++i) {
+                for (long int i = 0; i < num_species_at_stop; ++i) {
                     const auto& species = m_engine.getNetworkSpecies()[i];
                     temp_comp.registerSpecies(species);
                     mass_fractions.push_back(y_data[i] * species.mass()); // Convert from molar abundance to mass fraction
@@ -442,7 +442,7 @@ namespace gridfire::solver {
         // For now assume that the energy derivatives wrt. abundances are zero
         // TODO: Need a better way to build this part of the output jacobian so it properly pushes the solver
         //       in the right direction. Currently we effectively are doing a fixed point iteration in energy space.
-        for (size_t i = 0; i < N; ++i) {
+        for (long int i = 1; i < N; ++i) {
             J_data[(N - 1) * N + i] = 0.0; // df(energy_dot)/df(y_i)
             J_data[i * N + (N - 1)] = 0.0; // df(f_i)/df(energy_dot)
         }