diff --git a/Tests/test_core_resources.py b/Tests/test_core_resources.py
index 30bea3e80..11f26d38e 100644
--- a/Tests/test_core_resources.py
+++ b/Tests/test_core_resources.py
@@ -129,14 +129,15 @@ class TestCoreMemory(PillowTestCase):
         Image.core.set_block_size(4096)
         Image.new('RGB', (256, 256))
         Image.new('RGB', (256, 256))
-        Image.core.clear_cache()
+        # Keep 16 blocks in cache
+        Image.core.clear_cache(16)
 
         stats = Image.core.get_stats()
         self.assertGreaterEqual(stats['new_count'], 2)
         self.assertGreaterEqual(stats['allocated_blocks'], 64)
         self.assertGreaterEqual(stats['reused_blocks'], 64)
-        self.assertGreaterEqual(stats['freed_blocks'], 64)
-        self.assertEqual(stats['blocks_cached'], 0)
+        self.assertGreaterEqual(stats['freed_blocks'], 48)
+        self.assertEqual(stats['blocks_cached'], 16)
 
     def test_large_images(self):
         Image.core.reset_stats()
diff --git a/_imaging.c b/_imaging.c
index be612c1b7..b7d1ec09b 100644
--- a/_imaging.c
+++ b/_imaging.c
@@ -3466,10 +3466,12 @@ _set_blocks_max(PyObject* self, PyObject* args)
 static PyObject*
 _clear_cache(PyObject* self, PyObject* args)
 {
-    if (!PyArg_ParseTuple(args, ":clear_cache"))
+    int i = 0;
+
+    if (!PyArg_ParseTuple(args, "|i:clear_cache", &i))
         return NULL;
     
-    ImagingMemoryClearCache(&ImagingDefaultArena, 0);
+    ImagingMemoryClearCache(&ImagingDefaultArena, i);
 
     Py_INCREF(Py_None);
     return Py_None;