diff --git a/awx/api/serializers.py b/awx/api/serializers.py
index 73704b88f8..e6efcf3609 100644
--- a/awx/api/serializers.py
+++ b/awx/api/serializers.py
@@ -29,6 +29,7 @@ from django.utils.functional import cached_property
 
 # Django REST Framework
 from rest_framework.exceptions import ValidationError, PermissionDenied
+from rest_framework.relations import ManyRelatedField
 from rest_framework import fields
 from rest_framework import serializers
 from rest_framework import validators
@@ -277,6 +278,16 @@ class BaseSerializer(serializers.ModelSerializer):
     created       = serializers.SerializerMethodField()
     modified      = serializers.SerializerMethodField()
 
+    def __init__(self, *args, **kwargs):
+        super(BaseSerializer, self).__init__(*args, **kwargs)
+        # The following lines fix the problem of being able to pass JSON dict into PrimaryKeyRelatedField.
+        data = kwargs.get('data', False)
+        if data:
+            for field_name, field_instance in six.iteritems(self.fields):
+                if isinstance(field_instance, ManyRelatedField) and not field_instance.read_only:
+                    if isinstance(data.get(field_name, False), dict):
+                        raise serializers.ValidationError(_('Cannot use dictionary for %s' % field_name))
+
     @property
     def version(self):
         """
diff --git a/awx/main/tests/unit/api/serializers/test_primary_key_related_field.py b/awx/main/tests/unit/api/serializers/test_primary_key_related_field.py
new file mode 100644
index 0000000000..0be6d3312e
--- /dev/null
+++ b/awx/main/tests/unit/api/serializers/test_primary_key_related_field.py
@@ -0,0 +1,16 @@
+# Python
+import pytest
+
+# Django Rest Framework
+from rest_framework.exceptions import ValidationError
+
+# AWX
+from awx.api.serializers import JobLaunchSerializer
+
+
+def test_primary_key_related_field():
+    # We are testing if the PrimaryKeyRelatedField in this serializer can take dictionary.
+    # PrimaryKeyRelatedField should not be able to take dictionary as input, and should raise a ValidationError.
+    data = {'credentials' : {'1': '2', '3':'4'}}
+    with pytest.raises(ValidationError):
+        JobLaunchSerializer(data=data)