diff --git a/CHANGES.md b/CHANGES.md
index c1f61cd..04b4032 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -2,7 +2,9 @@
 
 ## 4.5.2 (not yet released)
 
-- #95 Fix breakage of `triton image create` in version 4.5.0. (By Kris Shannon.)
+- #95 Fix breakage of `triton image create` in v4.5.0. (By Kris Shannon.)
+- #94, #93 `triton inst create ...` is broken if "images.json" cache file
+  is missing. (By Kris Shannon.)
 
 
 ## 4.5.1
diff --git a/lib/tritonapi.js b/lib/tritonapi.js
index bd7cea7..9712caa 100644
--- a/lib/tritonapi.js
+++ b/lib/tritonapi.js
@@ -205,6 +205,15 @@ TritonApi.prototype._cachePutJson = function _cachePutJson(key, obj, cb) {
     });
 };
 
+/**
+ * Lookup the given key in the cache and return a hit or `undefined`.
+ *
+ * @param {String} key: The cache key, e.g. 'images.json'.
+ * @param {Function} cb: `function (err, hit)`.
+ *      `err` is an Error if there was an unexpected error loading from the
+ *      cache. `hit` is undefined if there was no cache hit. On a hit, the
+ *      type of `hit` depends on the key.
+ */
 TritonApi.prototype._cacheGetJson = function _cacheGetJson(key, cb) {
     var self = this;
     assert.string(this.cacheDir, 'this.cacheDir');