diff --git a/lib/ansible/module_common.py b/lib/ansible/module_common.py
index 7b3b37af846..06527c7680d 100644
--- a/lib/ansible/module_common.py
+++ b/lib/ansible/module_common.py
@@ -179,6 +179,7 @@ class AnsibleModule(object):
 
         if not bypass_checks:
             self._check_required_arguments()
+            self._check_argument_values()
             self._check_argument_types()
             self._check_mutually_exclusive(mutually_exclusive)
             self._check_required_together(required_together)
@@ -535,7 +536,7 @@ class AnsibleModule(object):
         if len(missing) > 0:
             self.fail_json(msg="missing required arguments: %s" % ",".join(missing))
 
-    def _check_argument_types(self):
+    def _check_argument_values(self):
         ''' ensure all arguments have the requested values, and there are no stray arguments '''
         for (k,v) in self.argument_spec.iteritems():
             choices = v.get('choices',None)
@@ -550,6 +551,45 @@ class AnsibleModule(object):
             else:
                 self.fail_json(msg="internal error: do not know how to interpret argument_spec")
 
+    def _check_argument_types(self):
+        ''' ensure all arguments have the requested type '''
+        for (k, v) in self.argument_spec.iteritems():
+            wanted = v.get('type', None)
+            if wanted is None:
+                continue
+            if k not in self.params:
+                continue
+
+            value = self.params[k]
+            is_invalid = False
+
+            if wanted == 'str':
+                if not isinstance(value, basestring):
+                    self.params[k] = str(value)
+            elif wanted == 'list':
+                if not isinstance(value, list):
+                    if isinstance(value, basestring):
+                        self.params[k] = value.split(",")
+                    else:
+                        is_invalid = True
+            elif wanted == 'dict':
+                if not isinstance(value, dict):
+                    if isinstance(value, basestring):
+                        self.params[k] = dict([x.split("=", 1) for x in value.split(",")])
+                    else:
+                        is_invalid = True
+            elif wanted == 'bool':
+                if not isinstance(value, bool):
+                    if isinstance(value, basestring):
+                        self.params[k] = self.boolean(value)
+                    else:
+                        is_invalid = True
+            else:
+                self.fail_json(msg="implementation error: unknown type %s requested for %s" % (wanted, k))
+
+            if is_invalid:
+                self.fail_json(msg="argument %s is of invalid type: %s, required: %s" % (k, type(value), wanted))
+
     def _set_defaults(self, pre=True):
          for (k,v) in self.argument_spec.iteritems():
              default = v.get('default', None)