diff --git a/bin/rmf_cat.cpp b/bin/rmf_cat.cpp
index 9ec94438..553f88f6 100644
--- a/bin/rmf_cat.cpp
+++ b/bin/rmf_cat.cpp
@@ -21,19 +21,42 @@ std::string output;
 }
 int main(int argc, char** argv) {
   try {
+    options.add_options()("force,f",
+                          "Combine files even if they have different "
+			  "structure or static frames.");
     positional_options.add_options()(
         "input-files,i",
         boost::program_options::value<std::vector<std::string> >(&inputs),
         "input rmf file");
     positional_names.emplace_back("input_1.rmf input_2.rmf ... output.rmf");
     positional_options_description.add("input-files", -1);
-    process_options(argc, argv);
+    boost::program_options::variables_map vm(process_options(argc, argv));
+
     if (inputs.size() < 3) {
       print_help_and_exit(argv);
     }
 
     output = inputs.back();
     inputs.pop_back();
+    bool force = vm.count("force");
+    if (!force && inputs.size() > 1) {
+      RMF::FileConstHandle rh1 = RMF::open_rmf_file_read_only(inputs[0]);
+      for (unsigned int i = 1; i < inputs.size(); ++i) {
+        RMF::FileConstHandle rh2 = RMF::open_rmf_file_read_only(inputs[i]);
+	if (!RMF::get_equal_structure(rh1, rh2, true)) {
+          std::cerr << inputs[0] << " and " << inputs[i]
+                    << " have different structure, cannot concatenate "
+                    << "without --force" << std::endl;
+          exit(1);
+	}
+	if (!RMF::get_equal_static_values(rh1, rh2)) {
+          std::cerr << inputs[0] << " and " << inputs[i]
+                    << " have different static frames, cannot concatenate "
+                    << "without --force" << std::endl;
+          exit(1);
+	}
+      }
+    }
     RMF::FileHandle orh = RMF::create_rmf_file(output);
     orh.set_producer("rmf_cat");
     for (unsigned int i = 0; i < inputs.size(); ++i) {
diff --git a/doc/Executables.md b/doc/Executables.md
index 5b1bb065..5924c29a 100644
--- a/doc/Executables.md
+++ b/doc/Executables.md
@@ -52,6 +52,7 @@ and how much they are used.
 
     Combine two or more rmf files.
     Usage: ./bin/rmf_cat input_1.rmf input_2.rmf ... output.rmf
+      -f [ --force ]        Combine files even if they have different structure or static frame.
       -h [ --help ]         Get help on command line arguments.
       -v [ --verbose ]      Produce more output.
       --hdf5-errors         Show hdf5 errors.
diff --git a/test/test_rmf_cat.py b/test/test_rmf_cat.py
new file mode 100644
index 00000000..6acfea27
--- /dev/null
+++ b/test/test_rmf_cat.py
@@ -0,0 +1,59 @@
+import unittest
+import os
+import RMF
+import subprocess
+
+
+class Tests(unittest.TestCase):
+
+    def test_help(self):
+        """Test rmf_cat --help"""
+        p = subprocess.Popen(['rmf_cat', '--help'], stdin=subprocess.PIPE,
+                             stdout=subprocess.PIPE,
+                             stderr=subprocess.PIPE,
+                             universal_newlines=True)
+        out, err = p.communicate()
+        self.assertEqual(out, "")
+        self.assertIn("Combine two or more rmf files", err)
+        self.assertEqual(p.returncode, 1)
+
+    def test_version(self):
+        """Test rmf_cat --version"""
+        p = subprocess.Popen(['rmf_cat', '--version'], stdin=subprocess.PIPE,
+                             stdout=subprocess.PIPE,
+                             stderr=subprocess.PIPE,
+                             universal_newlines=True)
+        out, err = p.communicate()
+        self.assertEqual(err, "")
+        self.assertIn("RMF version", out)
+        self.assertEqual(p.returncode, 0)
+
+    def test_cat_mismatch(self):
+        """Test rmf_cat of mismatched files"""
+        p = subprocess.Popen(
+            ['rmf_cat', RMF._get_test_input_file_path("simple.rmf"),
+             RMF._get_test_input_file_path("rep_and_geom.rmf"),
+             'test_cat_mismatch.rmf'],
+            stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE, universal_newlines=True)
+        out, err = p.communicate()
+        self.assertIn("have different structure", err)
+        self.assertEqual(p.returncode, 1)
+
+    def test_cat_ok(self):
+        """Test rmf_cat of similar files"""
+        p = subprocess.Popen(
+            ['rmf_cat', RMF._get_test_input_file_path("simple.rmf"),
+             RMF._get_test_input_file_path("simple-new.rmf"),
+             'test_cat_ok.rmf'],
+            stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE, universal_newlines=True)
+        out, err = p.communicate()
+        self.assertEqual(out, "")
+        self.assertEqual(err, "")
+        self.assertEqual(p.returncode, 0)
+        os.unlink('test_cat_ok.rmf')
+
+
+if __name__ == '__main__':
+    unittest.main()