diff --git a/gen/gen_decl.py b/gen/gen_decl.py
index 1005b95..696b4e0 100755
--- a/gen/gen_decl.py
+++ b/gen/gen_decl.py
@@ -9,8 +9,8 @@ sys.path.append(os.path.join(os.path.dirname(__file__), "..", "mpiabi"))
 
 from mpi_constants import constants
 from mpi_functions import functions
-from mpi_constants_fortran import constants_fortran
-from mpi_functions_fortran import functions_fortran
+# from mpi_constants_fortran import constants_fortran
+# from mpi_functions_fortran import functions_fortran
 
 support_profiling = True
 have_weak_symbols = False
@@ -24,7 +24,7 @@ def wrap(line):
     lines.append(line)
     return "\n".join(lines)
 
-with open("include/mpi_decl_constants_c.h", "w") as file:
+with open(sys.argv[1], "w") as file:
     file.write("// Declare C MPI constants\n")
     file.write("\n")
     for (tp, nm) in constants:
@@ -32,7 +32,7 @@ with open("include/mpi_decl_constants_c.h", "w") as file:
                 'mpi_nm': nm}
         file.write(Template("extern $mpi_tp MPITRAMPOLINE_CONST $mpi_nm;\n").substitute(subs))
 
-with open("include/mpi_decl_functions_c.h", "w") as file:
+with open(sys.argv[2], "w") as file:
     file.write("// Declare C MPI functions\n")
     file.write("\n")
     for (tp, nm, args, flags) in functions:
@@ -90,7 +90,7 @@ with open("include/mpi_decl_functions_c.h", "w") as file:
         file.write(Template("\n".join(tmpl)).substitute(subs))
         file.write("\n")
 
-with open("include/mpi_decl_constants_fortran.h", "w") as file:
+if False:
     file.write("!     Declare Fortran MPI constants\n")
     file.write("\n")
     for (tp, nm) in constants_fortran:
@@ -104,7 +104,7 @@ with open("include/mpi_decl_constants_fortran.h", "w") as file:
         file.write("\n".join(map(lambda line: wrap(Template(line).substitute(subs)), tmpl)))
         file.write("\n")
 
-with open("include/mpi_decl_functions_fortran.h", "w") as file:
+if False:
     file.write("!     Declare Fortran MPI functions\n")
     file.write("\n")
     for (tp, nm, args) in functions_fortran:
diff --git a/gen/gen_defn.py b/gen/gen_defn.py
index bf31f35..318222e 100755
--- a/gen/gen_defn.py
+++ b/gen/gen_defn.py
@@ -9,14 +9,14 @@ sys.path.append(os.path.join(os.path.dirname(__file__), "..", "mpiabi"))
 
 from mpi_constants import constants
 from mpi_functions import functions
-from mpi_constants_fortran import constants_fortran
-from mpi_functions_fortran import functions_fortran
+# from mpi_constants_fortran import constants_fortran
+# from mpi_functions_fortran import functions_fortran
 
 support_profiling = True
 have_weak_symbols = False
 replace_sentinels = False
 
-with open("src/mpi_defn_constants_c.h", "w") as file:
+with open(sys.argv[1], "w") as file:
     file.write("// Define C MPI constants")
     file.write("\n")
     for (tp, nm) in constants:
@@ -24,7 +24,7 @@ with open("src/mpi_defn_constants_c.h", "w") as file:
                 'mpi_nm': nm}
         file.write(Template("$mpi_tp $mpi_nm = ($mpi_tp)0xdeadbeef;\n").substitute(subs))
 
-with open("src/mpi_defn_functions_c.h", "w") as file:
+with open(sys.argv[2], "w") as file:
     file.write("// Define C MPI functions\n")
     file.write("\n")
     for (tp, nm, args, flags) in functions:
@@ -89,7 +89,7 @@ with open("src/mpi_defn_functions_c.h", "w") as file:
         file.write(Template("\n".join(tmpl)).substitute(subs))
         file.write("\n")
 
-with open("src/mpi_defn_constants_fortran.h", "w") as file:
+if False:
     file.write("// Define Fortran MPI constants\n")
     file.write("\n")
     for (tp, nm) in constants_fortran:
@@ -98,7 +98,7 @@ with open("src/mpi_defn_constants_fortran.h", "w") as file:
         # Fortran common blocks with `-march=skylake-avx512` are aligned to 64 bytes
         file.write(Template("$mpi_tp $abi_nm __attribute__((__aligned__(64))) = (int)0xdeadbeef;\n").substitute(subs))
 
-with open("src/mpi_defn_functions_fortran.h", "w") as file:
+if False:
     file.write("// Define Fortran MPI functions\n")
     file.write("\n")
     for (tp, nm, args) in functions_fortran:
diff --git a/gen/gen_init.py b/gen/gen_init.py
index 4939261..0e52822 100755
--- a/gen/gen_init.py
+++ b/gen/gen_init.py
@@ -9,14 +9,14 @@ sys.path.append(os.path.join(os.path.dirname(__file__), "..", "mpiabi"))
 
 from mpi_constants import constants
 from mpi_functions import functions
-from mpi_constants_fortran import constants_fortran
-from mpi_functions_fortran import functions_fortran
+# from mpi_constants_fortran import constants_fortran
+# from mpi_functions_fortran import functions_fortran
 
 support_profiling = True
 have_weak_symbols = False
 replace_sentinels = False
 
-with open("src/mpi_init_constants_c.h", "w") as file:
+with open(sys.argv[1], "w") as file:
     file.write("// Initialize C MPI constants")
     file.write("\n")
     for (tp, nm) in constants:
@@ -25,7 +25,7 @@ with open("src/mpi_init_constants_c.h", "w") as file:
                 'abi_nm': re.sub(r"MPI(X?)_", r"MPI\1ABI_", nm)}
         file.write(Template("$mpi_nm = *($mpi_tp const *)get_symbol(handle, \"$abi_nm\");\n").substitute(subs))
 
-with open("src/mpi_init_functions_c.h", "w") as file:
+with open(sys.argv[2], "w") as file:
     file.write("// Initialize C MPI functions\n")
     file.write("\n")
     for (tp, nm, args, flags) in functions:
@@ -39,7 +39,7 @@ with open("src/mpi_init_functions_c.h", "w") as file:
             subs['anm{0}'.format(i)] = anm
         file.write(Template("$abi_nm = get_symbol(handle, \"$abi_nm\");\n").substitute(subs))
 
-with open("src/mpi_init_constants_fortran.h", "w") as file:
+if False:
     file.write("// Initialize Fortran MPI constants\n")
     file.write("\n")
     for (tp, nm) in constants_fortran:
@@ -47,7 +47,7 @@ with open("src/mpi_init_constants_fortran.h", "w") as file:
                 'abi_nm': re.sub(r"MPI(X?)_", r"MPI\1ABI_", nm).lower() + "_"}
         file.write(Template("$abi_nm = *($abi_tp const*)get_symbol(handle, \"$abi_nm\");\n").substitute(subs))
 
-with open("src/mpi_init_functions_fortran.h", "w") as file:
+if False:
     file.write("// Initialize Fortran MPI functions\n")
     file.write("\n")
     for (tp, nm, args) in functions_fortran: