diff --git a/CHANGELOG.md b/CHANGELOG.md
index b7dab6e..462474b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file. This change
 
 ## [Unreleased]
 ### Fixed
+- Upcall stubs with non-primitive arguments failed to compile
 - Upcall stubs had incorrect types
 
 ## [0.1.176] - 2021-09-29
diff --git a/src/clj/coffi/ffi.clj b/src/clj/coffi/ffi.clj
index ec04dce..ed93bfc 100644
--- a/src/clj/coffi/ffi.clj
+++ b/src/clj/coffi/ffi.clj
@@ -320,7 +320,7 @@
                      [:getfield :this "upcall_ifn" IFn]
                      (map-indexed
                       (fn [idx arg]
-                        [[(load-instructions arg) (inc idx)]
+                        [[(load-instructions arg :aload) (inc idx)]
                          (to-object-asm arg)])
                       arg-types)
                      [:invokeinterface IFn "invoke" (repeat (inc (count arg-types)) Object)]