diff --git a/java/ql/src/Violations of Best Practice/legacy/AutoBoxing.ql b/java/ql/src/Violations of Best Practice/legacy/AutoBoxing.ql
index b80f86cd810..c6d8d796309 100644
--- a/java/ql/src/Violations of Best Practice/legacy/AutoBoxing.ql	
+++ b/java/ql/src/Violations of Best Practice/legacy/AutoBoxing.ql	
@@ -72,12 +72,16 @@ predicate rebox(Assignment e, Variable v) {
 
 from Expr e, string conv
 where
-  boxed(e) and conv = "This expression is implicitly boxed."
-  or
-  unboxed(e) and conv = "This expression is implicitly unboxed."
-  or
-  exists(Variable v | rebox(e, v) |
-    conv =
-      "This expression implicitly unboxes, updates, and reboxes the value of '" + v.getName() + "'."
+  e.getFile().isJavaSourceFile() and
+  (
+    boxed(e) and conv = "This expression is implicitly boxed."
+    or
+    unboxed(e) and conv = "This expression is implicitly unboxed."
+    or
+    exists(Variable v | rebox(e, v) |
+      conv =
+        "This expression implicitly unboxes, updates, and reboxes the value of '" + v.getName() +
+          "'."
+    )
   )
 select e, conv
diff --git a/java/ql/test/kotlin/query-tests/AutoBoxing/AutoBoxing.expected b/java/ql/test/kotlin/query-tests/AutoBoxing/AutoBoxing.expected
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/java/ql/test/kotlin/query-tests/AutoBoxing/AutoBoxing.qlref b/java/ql/test/kotlin/query-tests/AutoBoxing/AutoBoxing.qlref
new file mode 100644
index 00000000000..f116f3bd8b4
--- /dev/null
+++ b/java/ql/test/kotlin/query-tests/AutoBoxing/AutoBoxing.qlref
@@ -0,0 +1 @@
+Violations of Best Practice/legacy/AutoBoxing.ql
diff --git a/java/ql/test/kotlin/query-tests/AutoBoxing/Test.kt b/java/ql/test/kotlin/query-tests/AutoBoxing/Test.kt
new file mode 100644
index 00000000000..ca3aa52b2c9
--- /dev/null
+++ b/java/ql/test/kotlin/query-tests/AutoBoxing/Test.kt
@@ -0,0 +1,5 @@
+fun foo(x: Int?) {
+    if (x != null) {
+        println(x)
+    }
+}