diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a5ba23..6ee0c1c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,8 @@
 
 ## Fixed
 
+- Resolved reflection in `lambdaisland.clj-diff.optimizations`
+
 ## Changed
 
 # 1.4.78 (2022-11-25 / 2c3cae0)
@@ -39,4 +41,4 @@
 
 # 1.1.55 (2020-08-19 / 77da754)
 
-First release of the lambdaisland/clj-diff fork of clj-diff.
\ No newline at end of file
+First release of the lambdaisland/clj-diff fork of clj-diff.
diff --git a/bin/kaocha b/bin/kaocha
index 4a31cbf..5abf841 100755
--- a/bin/kaocha
+++ b/bin/kaocha
@@ -1,2 +1,2 @@
 #!/usr/bin/env bash
-clojure -A:dev:test -m kaocha.runner "$@"
+clojure -M:dev:test -m kaocha.runner "$@"
diff --git a/src/clj/lambdaisland/clj_diff/optimizations.clj b/src/clj/lambdaisland/clj_diff/optimizations.clj
index c8ba1ea..abe1fbe 100644
--- a/src/clj/lambdaisland/clj_diff/optimizations.clj
+++ b/src/clj/lambdaisland/clj_diff/optimizations.clj
@@ -3,6 +3,8 @@
   See http://neil.fraser.name/writing/diff/."
   (:import lambdaisland.clj_diff.FastStringOps))
 
+(set! *warn-on-reflection* true)
+
 (defn common-prefix [^String a ^String b]
   (let [i (FastStringOps/commonPrefix a b)]
     [i (.substring a i) (.substring b i)]))
@@ -17,7 +19,7 @@
   "Return a diff if the shorter sequence exists in the longer one. No need to
   use the expensive diff algorithm for this."
   [^String a ^String b ^Integer ca ^Integer cb]
-  (let [[short long] (if (> ca cb) [b a] [a b])
+  (let [[^String short ^String long] (if (> ca cb) [b a] [a b])
         i (int (.indexOf long short))]
     (if (= i -1)
       nil