diff --git a/include/openmc/tallies/filter.h b/include/openmc/tallies/filter.h
index 7920191aa1..bf31e65009 100644
--- a/include/openmc/tallies/filter.h
+++ b/include/openmc/tallies/filter.h
@@ -12,19 +12,6 @@
 
 namespace openmc {
 
-//==============================================================================
-// Global variables
-//==============================================================================
-
-extern "C" int32_t n_filters;
-
-class FilterMatch;
-extern std::vector<FilterMatch> filter_matches;
-#pragma omp threadprivate(filter_matches)
-
-class Filter;
-extern std::vector<Filter*> tally_filters;
-
 //==============================================================================
 //! Stores bins and weights for filtered tally events.
 //==============================================================================
@@ -36,6 +23,10 @@ public:
   std::vector<double> weights_;
 };
 
+// Without an explicit instantiation of vector<FilterMatch>, the Intel compiler
+// will complain about the threadprivate directive on filter_matches
+template class std::vector<FilterMatch>;
+
 //==============================================================================
 //! Modifies tally score events.
 //==============================================================================
@@ -76,6 +67,17 @@ public:
   int n_bins_;
 };
 
+//==============================================================================
+// Global variables
+//==============================================================================
+
+extern "C" int32_t n_filters;
+
+extern std::vector<FilterMatch> filter_matches;
+#pragma omp threadprivate(filter_matches)
+
+extern std::vector<Filter*> tally_filters;
+
 //==============================================================================
 
 extern "C" void free_memory_tally_c();
diff --git a/src/mesh.cpp b/src/mesh.cpp
index a9b716ecd5..bfdb370bb0 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -476,7 +476,7 @@ void RegularMesh::bins_crossed(const Particle* p, std::vector<int>& bins,
       // The track exits this cell.  Determine the distance to the closest mesh
       // surface.
       xt::xtensor<double, 1> d = xt::zeros<double>({n});
-      for (int j = 0; j < n; ++j) {
+      for (j = 0; j < n; ++j) {
         if (std::fabs(u[j]) < FP_PRECISION) {
           d(j) = INFTY;
         } else if (u[j] > 0) {
diff --git a/src/mesh_header.F90 b/src/mesh_header.F90
index d7e26fc6b8..a0c14077a8 100644
--- a/src/mesh_header.F90
+++ b/src/mesh_header.F90
@@ -140,21 +140,21 @@ module mesh_header
 
     pure function mesh_get_bin(ptr, xyz) result(bin) bind(C)
       import C_PTR, C_DOUBLE, C_INT
-      type(C_PTR), value :: ptr
+      type(C_PTR), intent(in), value :: ptr
       real(C_DOUBLE), intent(in) :: xyz(*)
       integer(C_INT) :: bin
     end function
 
     pure function mesh_get_bin_from_indices(ptr, ijk) result(bin) bind(C)
       import C_PTR, C_INT
-      type(C_PTR), value :: ptr
+      type(C_PTR), intent(in), value :: ptr
       integer(C_INT), intent(in) :: ijk(*)
       integer(C_INT) :: bin
     end function
 
     pure subroutine mesh_get_indices(ptr, xyz, ijk, in_mesh) bind(C)
       import C_PTR, C_DOUBLE, C_INT, C_BOOL
-      type(C_PTR), value :: ptr
+      type(C_PTR), intent(in), value :: ptr
       real(C_DOUBLE), intent(in) :: xyz(*)
       integer(C_INT), intent(out) :: ijk(*)
       logical(C_BOOL), intent(out) :: in_mesh
@@ -162,8 +162,8 @@ module mesh_header
 
     pure subroutine mesh_get_indices_from_bin(ptr, bin, ijk) bind(C)
       import C_PTR, C_INT
-      type(C_PTR), value :: ptr
-      integer(C_INT), value :: bin
+      type(C_PTR), intent(in), value :: ptr
+      integer(C_INT), intent(in), value :: bin
       integer(C_INT), intent(out) :: ijk(*)
     end subroutine
 
diff --git a/src/reaction_header.F90 b/src/reaction_header.F90
index 9d6add0f0a..0762846efc 100644
--- a/src/reaction_header.F90
+++ b/src/reaction_header.F90
@@ -74,22 +74,22 @@ module reaction_header
 
     pure function reaction_product_decay_rate(ptr, product) result(rate) bind(C)
       import C_PTR, C_INT, C_DOUBLE
-      type(C_PTR), value :: ptr
-      integer(C_INT), value :: product
+      type(C_PTR), intent(in), value :: ptr
+      integer(C_INT), intent(in), value :: product
       real(C_DOUBLE) :: rate
     end function
 
     pure function reaction_product_emission_mode(ptr, product) result(m) bind(C)
       import C_PTR, C_INT
-      type(C_PTR), value :: ptr
-      integer(C_INT), value :: product
+      type(C_PTR), intent(in), value :: ptr
+      integer(C_INT), intent(in), value :: product
       integer(C_INT) :: m
     end function
 
     pure function reaction_product_particle(ptr, product) result(particle) bind(C)
       import C_PTR, C_INT
-      type(C_PTR), value :: ptr
-      integer(C_INT), value :: product
+      type(C_PTR), intent(in), value :: ptr
+      integer(C_INT), intent(in), value :: product
       integer(C_INT) :: particle
     end function
 
@@ -104,15 +104,15 @@ module reaction_header
 
     pure function reaction_product_yield(ptr, product, E) result(val) bind(C)
       import C_PTR, C_INT, C_DOUBLE
-      type(C_PTR), value :: ptr
-      integer(C_INT), value :: product
-      real(C_DOUBLE), value :: E
+      type(C_PTR), intent(in), value :: ptr
+      integer(C_INT), intent(in), value :: product
+      real(C_DOUBLE), intent(in), value :: E
       real(C_DOUBLE) :: val
     end function
 
     pure function reaction_products_size(ptr) result(sz) bind(C)
       import C_PTR, C_INT
-      type(C_PTR), value :: ptr
+      type(C_PTR), intent(in), value :: ptr
       integer(C_INT) :: sz
     end function