diff --git a/CHANGELOG.md b/CHANGELOG.md
index 07295f6..717ee20 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
+- Primitive-serializing types fail to compile as arguments to downcall handles
 - Primitive-serializing types fail to load as arguments to upcall functions
 - Void return types on upcalls crash the JVM
 - Invalid implementation of serialize-into for primitive types
diff --git a/src/clj/coffi/ffi.clj b/src/clj/coffi/ffi.clj
index 66f5772..75c6b6a 100644
--- a/src/clj/coffi/ffi.clj
+++ b/src/clj/coffi/ffi.clj
@@ -108,9 +108,10 @@
 (defn- insn-layout
   "Gets the type keyword or class for referring to the type in bytecode."
   [type]
-  (if (some-> (mem/primitive-type type) (not= ::mem/pointer))
-    (keyword (name type))
-    (mem/java-layout type)))
+  (when-some [prim (mem/primitive-type type)]
+    (if (not= prim ::mem/pointer)
+      (keyword (name prim))
+      (mem/java-layout type))))
 
 (def ^:private unbox-fn-for-type
   "Map from type name to the name of its unboxing function."