diff --git a/kitty/disk-cache.h b/kitty/disk-cache.h
index 2b424704a..de84334bf 100644
--- a/kitty/disk-cache.h
+++ b/kitty/disk-cache.h
@@ -12,5 +12,14 @@ PyObject* create_disk_cache(void);
 bool add_to_disk_cache(PyObject *self, const void *key, size_t key_sz, const void *data, size_t data_sz);
 bool remove_from_disk_cache(PyObject *self_, const void *key, size_t key_sz);
 void* read_from_disk_cache(PyObject *self_, const void *key, size_t key_sz, void*(allocator)(void*, size_t), void*);
-static inline void* disk_cache_malloc_allocator(void *x UNUSED, size_t sz) { return malloc(sz); }
-static inline void* read_from_disk_cache_simple(PyObject *self_, const void *key, size_t key_sz) { return read_from_disk_cache(self_, key, key_sz, disk_cache_malloc_allocator, NULL); }
+
+static inline void* disk_cache_malloc_allocator(void *x, size_t sz) {
+    *((size_t*)x) = sz;
+    return malloc(sz);
+}
+
+static inline bool
+read_from_disk_cache_simple(PyObject *self_, const void *key, size_t key_sz, void **data, size_t *data_sz) {
+    *data = read_from_disk_cache(self_, key, key_sz, disk_cache_malloc_allocator, data_sz);
+    return PyErr_Occurred();
+}