diff --git a/Makefile b/Makefile
index 296013999a..0b2ebc77e8 100644
--- a/Makefile
+++ b/Makefile
@@ -507,6 +507,31 @@ llvm:
 	"OPENMP = $(OPENMP)" \
 	"CPPFLAGS = $(MODEL_FORMULATION) -D_MPI" )
 
+nag:
+	( $(MAKE) all \
+	"FC_PARALLEL = mpifort" \
+	"CC_PARALLEL = mpicc" \
+	"CXX_PARALLEL = mpic++" \
+	"FC_SERIAL = nagfor" \
+	"CC_SERIAL = gcc" \
+	"CXX_SERIAL = g++" \
+	"FFLAGS_PROMOTION = -r8" \
+	"FFLAGS_OPT = -free -mismatch -O3 -convert=big_ieee" \
+	"CFLAGS_OPT = -O3" \
+	"CXXFLAGS_OPT = -O3" \
+	"LDFLAGS_OPT = -O3" \
+	"FFLAGS_DEBUG = -free -mismatch -O0 -g -C -convert=big_ieee" \
+	"CFLAGS_DEBUG = -O0 -g -Wall -pedantic" \
+	"CXXFLAGS_DEBUG = -O0 -g -Wall -pedantic" \
+	"LDFLAGS_DEBUG = -O0 -g -C" \
+	"FFLAGS_OMP = -qsmp=omp" \
+	"CFLAGS_OMP = -qsmp=omp" \
+	"CORE = $(CORE)" \
+	"DEBUG = $(DEBUG)" \
+	"USE_PAPI = $(USE_PAPI)" \
+	"OPENMP = $(OPENMP)" \
+	"CPPFLAGS = $(MODEL_FORMULATION) -D_MPI -DUNDERSCORE -DNAG_COMPILER" )
+
 CPPINCLUDES =
 FCINCLUDES =
 LIBS =
diff --git a/src/external/Makefile b/src/external/Makefile
index 4409d9c704..afb7533445 100644
--- a/src/external/Makefile
+++ b/src/external/Makefile
@@ -3,7 +3,7 @@
 all: esmf_time ezxml-lib
 
 esmf_time:
-	( cd esmf_time_f90; $(MAKE) FC="$(FC) $(FFLAGS)" CPP="$(CPP)" CPPFLAGS="$(CPPFLAGS) -DHIDE_MPI" GEN_F90=$(GEN_F90) )
+	( cd esmf_time_f90; $(MAKE) FC="$(FC)" FFLAGS="$(FFLAGS)" CPP="$(CPP)" CPPFLAGS="$(CPPFLAGS) -DHIDE_MPI" GEN_F90=$(GEN_F90) )
 
 ezxml-lib:
 	( cd ezxml; $(MAKE) )
diff --git a/src/operators/mpas_spline_interpolation.F b/src/operators/mpas_spline_interpolation.F
index f7fa682842..6d0d2ffa02 100644
--- a/src/operators/mpas_spline_interpolation.F
+++ b/src/operators/mpas_spline_interpolation.F
@@ -115,6 +115,10 @@ subroutine mpas_interpolate_cubic_spline( &!{{{
 
 ! INPUT PARAMETERS:
 
+  integer, intent(in) :: &
+    n,      &!< Input: number of nodes, input grid
+    nOut       !< Input: number of nodes, output grid
+
   real (kind=RKIND), dimension(n), intent(in) :: &
     x,         &!< Input: node location, input grid
     y,       &!< Input: interpolation variable, input grid
@@ -123,10 +127,6 @@ subroutine mpas_interpolate_cubic_spline( &!{{{
   real (kind=RKIND), dimension(nOut), intent(in) :: &
     xOut          !< Input: node location, output grid
 
-  integer, intent(in) :: &
-    n,      &!< Input: number of nodes, input grid
-    nOut       !< Input: number of nodes, output grid
-
 ! OUTPUT PARAMETERS:
 
   real (kind=RKIND), dimension(nOut), intent(out) :: &
@@ -359,6 +359,10 @@ subroutine mpas_interpolate_linear( &!{{{
 
 ! !INPUT PARAMETERS:
 
+  integer, intent(in) :: &
+    N,      &!< Input: number of nodes, input grid
+    NOut       !< Input: number of nodes, output grid
+
   real (kind=RKIND), dimension(n), intent(in) :: &
     x,         &!< Input: node location, input grid
     y         !< Input: interpolation variable, input grid
@@ -366,10 +370,6 @@ subroutine mpas_interpolate_linear( &!{{{
   real (kind=RKIND), dimension(nOut), intent(in) :: &
     xOut          !< Input: node location, output grid
 
-  integer, intent(in) :: &
-    N,      &!< Input: number of nodes, input grid
-    NOut       !< Input: number of nodes, output grid
-
 ! !OUTPUT PARAMETERS:
 
   real (kind=RKIND), dimension(nOut), intent(out) :: &
diff --git a/src/tools/registry/gen_inc.c b/src/tools/registry/gen_inc.c
index 4f49089a11..eb9395016a 100644
--- a/src/tools/registry/gen_inc.c
+++ b/src/tools/registry/gen_inc.c
@@ -653,7 +653,11 @@ int parse_namelist_records_from_registry(ezxml_t registry)/*{{{*/
 		}
 
 		fortprintf(fd, "      if (dminfo %% my_proc_id == IO_NODE) then\n");
+		fortprintf(fd, "! Rewinding before each read leads to errors when the code is built with\n");
+		fortprintf(fd, "! the NAG Fortran compiler. If building with NAG, be kind and don't rewind.\n");
+		fortprintf(fd, "#ifndef NAG_COMPILER\n");
 		fortprintf(fd, "         rewind(unitNumber)\n");
+		fortprintf(fd, "#endif\n");
 		fortprintf(fd, "         read(unitNumber, %s, iostat=ierr)\n", nmlrecname);
 		fortprintf(fd, "      end if\n");