diff --git a/access-token-provider-api/src/test/java/net/ihe/gazelle/app/accesstokenproviderapi/application/TokenGeneratorTest.java b/access-token-provider-api/src/test/java/net/ihe/gazelle/app/accesstokenproviderapi/application/TokenGeneratorTest.java
index c3b27b9bf94031932f1a84b22864fe2183c8ea96..4e21eba398ce593ac0090aba790db034bfc2c3b3 100644
--- a/access-token-provider-api/src/test/java/net/ihe/gazelle/app/accesstokenproviderapi/application/TokenGeneratorTest.java
+++ b/access-token-provider-api/src/test/java/net/ihe/gazelle/app/accesstokenproviderapi/application/TokenGeneratorTest.java
@@ -207,6 +207,19 @@ class TokenGeneratorTest {
         accessTokenRequest.setSignature(new SymmetricSignature(ALGORITHM, "secret"));
 
 
+        TokenGenerator tokenGenerator = new TokenGenerator();
+        tokenGenerator.setAudienceSecretRetriever(audience -> null);
+
+        assertThrows(TokenRequestException.class, () -> tokenGenerator.generateAccessToken(accessTokenRequest), "Unsupported issuer");
+    }
+
+
+    @Test
+    public void generateAccessTokenDurationNullTest() throws EncodingException, TokenRequestException {
+        AccessTokenRequest accessTokenRequest = new AccessTokenRequest(ISSUER, SUBJECT, "pouet", null, TOKEN_TYPE);
+        accessTokenRequest.setSignature(new SymmetricSignature(ALGORITHM, "secret"));
+
+
         TokenGenerator tokenGenerator = new TokenGenerator();
         tokenGenerator.setAudienceSecretRetriever(audience -> null);