diff --git a/Inst_eddies/Tests/Input/main_nml.txt b/Inst_eddies/Tests/Input/main_nml.txt
deleted file mode 100644
index 801a3406d16c69528eb32ec45bc753bd44216afd..0000000000000000000000000000000000000000
--- a/Inst_eddies/Tests/Input/main_nml.txt
+++ /dev/null
@@ -1 +0,0 @@
-&main_nml /
diff --git a/Inst_eddies/Tests/long_tests.json b/Inst_eddies/Tests/long_tests.json
index 3d491e3c424b52c138a3aea99909ce584fb7410a..04da56a5ce2370cec6bcbdf56d4bbe8372a29466 100644
--- a/Inst_eddies/Tests/long_tests.json
+++ b/Inst_eddies/Tests/long_tests.json
@@ -71,7 +71,7 @@
 	]
     },
     {
-        "required": ["$src_dir/Inst_eddies/Tests/Input/main_nml.txt"],
+        "input": "&main_nml /\n",
         "title": "Region_6",
         "command":
 	[
@@ -82,7 +82,7 @@
         ]
     },
     {
-        "required": ["$src_dir/Inst_eddies/Tests/Input/main_nml.txt"],
+        "input": "&main_nml /\n",
         "title": "Missing_file",
         "command":
 	[
diff --git a/Inst_eddies/Tests/short_tests.json b/Inst_eddies/Tests/short_tests.json
index 7dfc03b09b27af435e139bc7eb9da6d3d4eb80ec..fc0bb38098bfb1706b18f3bceb39bff1061a0452 100644
--- a/Inst_eddies/Tests/short_tests.json
+++ b/Inst_eddies/Tests/short_tests.json
@@ -292,7 +292,7 @@
     },
     {
         "description": "Part of the domain has missing values.",
-        "required": ["$src_dir/Inst_eddies/Tests/Input/main_nml.txt"],
+        "input": "&main_nml /\n",
         "title": "Extraction_eddies_region_4",
         "command":
 	[
@@ -306,7 +306,7 @@
     {
       "description":
       "Like Extraction_eddies_region_4, but for a single date. This is a test of options of the wrapper script rather than a test of the Fortran executable.",
-      "required": ["$src_dir/Inst_eddies/Tests/Input/main_nml.txt"],
+      "input": "&main_nml /\n",
       "title": "Inst_eddies_py",
       "command":
       [
@@ -316,7 +316,7 @@
       ]
     },
     {
-        "required": ["$src_dir/Inst_eddies/Tests/Input/main_nml.txt"],
+        "input": "&main_nml /\n",
         "title": "Inst_eddies_loop",
         "command":
 	[
diff --git a/Inst_eddies/inst_eddies_in.py b/Inst_eddies/inst_eddies_in.py
index ab2dab1e6ba45ddc030fc4bd9d1693c27aa7f151..3ab8d4d7b5d16746d8946d7a08b527de23487a0b 100755
--- a/Inst_eddies/inst_eddies_in.py
+++ b/Inst_eddies/inst_eddies_in.py
@@ -28,10 +28,6 @@ argparser.add_argument("-l", "--last_date", help = "%%Y-%%m-%%d")
 argparser.add_argument("-b", "--bbox", nargs=4, type = float,
                        metavar = ("xmin", "xmax", "ymin", "ymax"))
 args = argparser.parse_args()
-
-if not os.access("main_nml.txt", os.R_OK):
-    sys.exit("main_nml.txt not found or not readable")
-
 inst_eddies_exe = "@CMAKE_CURRENT_BINARY_DIR@/inst_eddies"
 
 if not os.access(inst_eddies_exe, os.X_OK):
@@ -84,12 +80,9 @@ while True:
         os.symlink(nc_file, "h.nc")
         os.symlink(nc_file, "uv.nc")
         elapsed_NCO = time.perf_counter() - my_pc
-        
-        with open("main_nml.txt") as nml_file:
-            my_pc = time.perf_counter()
-            subprocess.run(inst_eddies_exe, stdin = nml_file, check = True)
-            elapsed_Fortran = time.perf_counter() - my_pc
-
+        my_pc = time.perf_counter()
+        subprocess.run(inst_eddies_exe, check = True)
+        elapsed_Fortran = time.perf_counter() - my_pc
         os.remove("h.nc")
         os.remove("uv.nc")
         writer.writerow([my_date, elapsed_NCO, elapsed_Fortran])