diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index b3ac035b6..3eaa1a4d1 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -176,9 +176,9 @@ class KeyPairBackend(object):
         return keypair
 
     def delete_key_pair(self, name):
-        keypair = self.keypairs.pop(name)
-        keypair['name'] = name
-        return keypair
+        if name in self.keypairs:
+            self.keypairs.pop(name)
+        return True
 
     def describe_key_pairs(self, filter_names=None):
         results = []
diff --git a/moto/ec2/responses/key_pairs.py b/moto/ec2/responses/key_pairs.py
index 68c25e71f..0e5fc47ae 100644
--- a/moto/ec2/responses/key_pairs.py
+++ b/moto/ec2/responses/key_pairs.py
@@ -18,7 +18,9 @@ class KeyPairs(BaseResponse):
             return template.render(**keypair)
 
     def delete_key_pair(self):
-        return Template(DELETE_KEY_PAIR_RESPONSE).render(success="true")
+        name = self.querystring.get('KeyName')[0]
+        success = str(ec2_backend.delete_key_pair(name)).lower()
+        return Template(DELETE_KEY_PAIR_RESPONSE).render(success=success)
 
     def describe_key_pairs(self):
         template = Template(DESCRIBE_KEY_PAIRS_RESPONSE)