diff --git a/hiero-spring/src/test/java/com/openelements/hiero/spring/test/FileClientTests.java b/hiero-spring/src/test/java/com/openelements/hiero/spring/test/FileClientTests.java
index a465be9..3c6dc69 100644
--- a/hiero-spring/src/test/java/com/openelements/hiero/spring/test/FileClientTests.java
+++ b/hiero-spring/src/test/java/com/openelements/hiero/spring/test/FileClientTests.java
@@ -26,6 +26,7 @@ void testNullParams() {
         Assertions.assertThrows(NullPointerException.class, () -> fileClient.readFile((FileId) null));
         Assertions.assertThrows(NullPointerException.class, () -> fileClient.deleteFile((String) null));
         Assertions.assertThrows(NullPointerException.class, () -> fileClient.deleteFile((FileId) null));
+        Assertions.assertThrows(NullPointerException.class, () -> fileClient.getExpirationTime(null));
     }
 
     @Test
@@ -200,6 +201,14 @@ void testGetExpirationTime() throws Exception {
         Assertions.assertTrue(expirationTime.isBefore(definedExpirationTime.plusSeconds(1)));
     }
 
+    @Test
+    void testGetExpirationTimeForFailures() {
+        //given
+        final FileId invalidFileId = FileId.fromString("1.2.3");
+        //then
+        Assertions.assertThrows(HieroException.class, () -> fileClient.getExpirationTime(invalidFileId));
+    }
+
     @Test
     @Disabled("Always fails with AUTORENEW_DURATION_NOT_IN_RANGE. Needs to be investigated further.")
     void testUpdateExpirationTime() throws Exception {