diff --git a/java/ql/test/kotlin/library-tests/java-map-methods/test.expected b/java/ql/test/kotlin/library-tests/java-map-methods/test.expected
index 0a646e52fe1..e2be3e08d16 100644
--- a/java/ql/test/kotlin/library-tests/java-map-methods/test.expected
+++ b/java/ql/test/kotlin/library-tests/java-map-methods/test.expected
@@ -1,2 +1,5 @@
+diagnostics
+| file://:0:0:0:0 | Couldn't find a Java equivalent function to kotlin.String.<get-length> in java.lang.String |
+#select
 | Integer |
 | Object |
diff --git a/java/ql/test/kotlin/library-tests/java-map-methods/test.kt b/java/ql/test/kotlin/library-tests/java-map-methods/test.kt
index 9a40d3c29bf..0edaadff5a1 100644
--- a/java/ql/test/kotlin/library-tests/java-map-methods/test.kt
+++ b/java/ql/test/kotlin/library-tests/java-map-methods/test.kt
@@ -1 +1,3 @@
 fun test(m: Map<Int, Int>) = m.getOrDefault(1, 2)
+
+fun test2(s: String) = s.length
diff --git a/java/ql/test/kotlin/library-tests/java-map-methods/test.ql b/java/ql/test/kotlin/library-tests/java-map-methods/test.ql
index 2694f59162d..259af0c8348 100644
--- a/java/ql/test/kotlin/library-tests/java-map-methods/test.ql
+++ b/java/ql/test/kotlin/library-tests/java-map-methods/test.ql
@@ -1,4 +1,7 @@
 import java
+import semmle.code.java.Diagnostics
 
 from MethodAccess ma
 select ma.getCallee().getAParameter().getType().toString()
+
+query predicate diagnostics(Diagnostic d) { any() }