diff --git a/kinto_http/__init__.py b/kinto_http/__init__.py
index 751c732..a6a63be 100644
--- a/kinto_http/__init__.py
+++ b/kinto_http/__init__.py
@@ -254,11 +254,7 @@ def delete_bucket(self, bucket=None, safe=True, if_match=None, if_exists=False):
         resp, _ = self.session.request('delete', endpoint, headers=headers)
         return resp['data']
 
-    def delete_buckets(self, safe=True, if_match=None, if_exists=False):
-        if if_exists:
-            return self._delete_if_exists('buckets',
-                                          safe=safe,
-                                          if_match=if_match)
+    def delete_buckets(self, safe=True, if_match=None):
         endpoint = self.get_endpoint('buckets')
         headers = self._get_cache_headers(safe, if_match=if_match)
         resp, _ = self.session.request('delete', endpoint, headers=headers)
@@ -415,12 +411,7 @@ def delete_collection(self, collection=None, bucket=None,
         resp, _ = self.session.request('delete', endpoint, headers=headers)
         return resp['data']
 
-    def delete_collections(self, bucket=None, safe=True, if_match=None, if_exists=False):
-        if if_exists:
-            return self._delete_if_exists('collections',
-                                          bucket=bucket,
-                                          safe=safe,
-                                          if_match=if_match)
+    def delete_collections(self, bucket=None, safe=True, if_match=None):
         endpoint = self.get_endpoint('collections', bucket=bucket)
         headers = self._get_cache_headers(safe, if_match=if_match)
         resp, _ = self.session.request('delete', endpoint, headers=headers)
@@ -523,13 +514,7 @@ def delete_record(self, id, collection=None, bucket=None,
         return resp['data']
 
     def delete_records(self, collection=None, bucket=None,
-                       safe=True, if_match=None, if_exists=False):
-        if if_exists:
-            return self._delete_if_exists('records',
-                                          collection=collection,
-                                          bucket=bucket,
-                                          safe=safe,
-                                          if_match=if_match)
+                       safe=True, if_match=None):
         endpoint = self.get_endpoint('records',
                                      bucket=bucket,
                                      collection=collection)
diff --git a/kinto_http/tests/functional.py b/kinto_http/tests/functional.py
index c0196d7..e751e08 100644
--- a/kinto_http/tests/functional.py
+++ b/kinto_http/tests/functional.py
@@ -94,10 +94,9 @@ def test_buckets_deletion(self):
         assert buckets[0]['id'] == 'mozilla'
         self.assertRaises(BucketNotFound, self.client.get_bucket, 'mozilla')
 
-    def test_buckets_deletion_if_exists(self):
-        self.client.create_bucket('mozilla')
-        self.client.delete_buckets()
-        self.client.delete_buckets(if_exists=True)
+    def test_buckets_deletion_when_no_buckets_exist(self):
+        deleted_buckets = self.client.delete_buckets()
+        assert len(deleted_buckets) == 0
 
     def test_bucket_save(self):
         self.client.create_bucket('mozilla', permissions={'write': ['alexis']})
@@ -180,6 +179,11 @@ def test_groups_deletion(self):
         self.client.delete_groups(bucket='mozilla')
         assert len(self.client.get_groups(bucket='mozilla')) == 0
 
+    def test_groups_deletion_when_no_groups_exist(self):
+        self.client.create_bucket('mozilla')
+        deleted_groups = self.client.delete_groups(bucket='mozilla')
+        assert len(deleted_groups) == 0
+
     def test_collection_creation(self):
         self.client.create_bucket('mozilla')
         self.client.create_collection(
@@ -235,12 +239,10 @@ def test_collections_deletion(self):
         self.client.delete_collections(bucket='mozilla')
         assert len(self.client.get_collections(bucket='mozilla')) == 0
 
-    def test_collections_deletion_if_exists(self):
+    def test_collections_deletion_when_no_collections_exist(self):
         self.client.create_bucket('mozilla')
-        self.client.create_collection('amo', bucket='mozilla')
-        self.client.create_collection('blocklist', bucket='mozilla')
-        self.client.delete_collections(bucket='mozilla')
-        self.client.delete_collections(bucket='mozilla', if_exists=True)
+        deleted_collections = self.client.delete_collections(bucket='mozilla')
+        assert len(deleted_collections) == 0
 
     def test_record_creation_and_retrieval(self):
         client = Client(server_url=self.server_url, auth=self.auth,
@@ -356,14 +358,13 @@ def test_multiple_record_deletion(self):
         client.delete_records()
         assert len(client.get_records()) == 0
 
-    def test_records_deletion_if_exists(self):
+    def test_records_deletion_when_no_records_exist(self):
         client = Client(server_url=self.server_url, auth=self.auth,
                         bucket='mozilla', collection='payments')
         client.create_bucket()
         client.create_collection()
-        client.create_record({'foo': 'bar'})
-        client.delete_records()
-        client.delete_records(if_exists=True)
+        deleted_records = client.delete_records()
+        assert len(deleted_records) == 0
 
     def test_bucket_sharing(self):
         alice_credentials = ('alice', 'p4ssw0rd')