diff --git a/cwltool/main.py b/cwltool/main.py
index 1c502c508..9ea819598 100755
--- a/cwltool/main.py
+++ b/cwltool/main.py
@@ -285,8 +285,13 @@ def generate_parser(toolparser, tool, namemap):
             _logger.debug(u"Can't make command line argument from %s", inptype)
             return None
 
+        if inptype != "boolean":
+            typekw = { 'type': atype }
+        else:
+            typekw = {}
+
         toolparser.add_argument(flag + name, required=required,
-                help=ahelp, action=action, type=atype, default=default)
+                help=ahelp, action=action, default=default, **typekw)
 
     return toolparser
 
diff --git a/tests/test_toolargparse.py b/tests/test_toolargparse.py
index 7504280ed..29bfeb34c 100644
--- a/tests/test_toolargparse.py
+++ b/tests/test_toolargparse.py
@@ -24,6 +24,24 @@ class ToolArgparse(unittest.TestCase):
       glob: test.txt
 stdout: test.txt
 baseCommand: [cat]
+'''
+
+    script2='''
+#!/usr/bin/env cwl-runner
+cwlVersion: 'cwl:draft-3'
+class: CommandLineTool
+inputs:
+  - id: bdg
+    type: "boolean"
+outputs:
+  - id: output
+    type: File
+    outputBinding:
+      glob: foo
+baseCommand:
+  - echo
+  - "ff"
+stdout: foo
 '''
 
     def test_help(self):
@@ -31,3 +49,12 @@ def test_help(self):
             f.write(self.script)
             f.flush()
             self.assertEquals(main([f.name, '--input', 'README.rst']), 0)
+
+    def test_bool(self):
+        with NamedTemporaryFile() as f:
+            f.write(self.script2)
+            f.flush()
+            try:
+                self.assertEquals(main([f.name, '--help']), 0)
+            except SystemExit as e:
+                self.assertEquals(e.code, 0)