diff --git a/test/webfuse/tests/adapter/test_credentials.cc b/test/webfuse/tests/adapter/test_credentials.cc
index 72350d4..88e2552 100644
--- a/test/webfuse/tests/adapter/test_credentials.cc
+++ b/test/webfuse/tests/adapter/test_credentials.cc
@@ -1,5 +1,6 @@
 #include <gtest/gtest.h>
 
+#include "webfuse/adapter/credentials.h"
 #include "webfuse/adapter/impl/credentials.h"
 #include <jansson.h>
 
@@ -8,7 +9,7 @@ TEST(Credentials, Type)
     struct wf_credentials creds;
 
     wf_impl_credentials_init(&creds, "test", nullptr);
-    ASSERT_STREQ("test", wf_impl_credentials_type(&creds));
+    ASSERT_STREQ("test", wf_credentials_type(&creds));
     wf_impl_credentials_cleanup(&creds);
 }
 
@@ -20,9 +21,9 @@ TEST(Credentials, Get)
     json_object_set_new(data, "password", json_string("<secret>"));
 
     wf_impl_credentials_init(&creds, "username", data);
-    ASSERT_STREQ("username", wf_impl_credentials_type(&creds));
-    ASSERT_STREQ("bob", wf_impl_credentials_get(&creds, "username"));
-    ASSERT_STREQ("<secret>", wf_impl_credentials_get(&creds, "password"));
+    ASSERT_STREQ("username", wf_credentials_type(&creds));
+    ASSERT_STREQ("bob", wf_credentials_get(&creds, "username"));
+    ASSERT_STREQ("<secret>", wf_credentials_get(&creds, "password"));
 
     wf_impl_credentials_cleanup(&creds);
     json_decref(data);
@@ -34,9 +35,9 @@ TEST(Credentials, FailedToGetNonexistingValue)
     json_t * data = json_object();
 
     wf_impl_credentials_init(&creds, "username", data);
-    ASSERT_STREQ("username", wf_impl_credentials_type(&creds));
-    ASSERT_STREQ(nullptr, wf_impl_credentials_get(&creds, "username"));
-    ASSERT_STREQ(nullptr, wf_impl_credentials_get(&creds, "password"));
+    ASSERT_STREQ("username", wf_credentials_type(&creds));
+    ASSERT_STREQ(nullptr, wf_credentials_get(&creds, "username"));
+    ASSERT_STREQ(nullptr, wf_credentials_get(&creds, "password"));
 
     wf_impl_credentials_cleanup(&creds);
     json_decref(data);    
@@ -47,9 +48,9 @@ TEST(Credentials, FailedToGetWithoutData)
     struct wf_credentials creds;
 
     wf_impl_credentials_init(&creds, "username", nullptr);
-    ASSERT_STREQ("username", wf_impl_credentials_type(&creds));
-    ASSERT_STREQ(nullptr, wf_impl_credentials_get(&creds, "username"));
-    ASSERT_STREQ(nullptr, wf_impl_credentials_get(&creds, "password"));
+    ASSERT_STREQ("username", wf_credentials_type(&creds));
+    ASSERT_STREQ(nullptr, wf_credentials_get(&creds, "username"));
+    ASSERT_STREQ(nullptr, wf_credentials_get(&creds, "password"));
 
     wf_impl_credentials_cleanup(&creds);
 }
@@ -60,11 +61,25 @@ TEST(Credentials, FailedToGetWrongDataType)
     json_t * data = json_string("invalid_creds");
 
     wf_impl_credentials_init(&creds, "username", data);
-    ASSERT_STREQ("username", wf_impl_credentials_type(&creds));
-    ASSERT_STREQ(nullptr, wf_impl_credentials_get(&creds, "username"));
-    ASSERT_STREQ(nullptr, wf_impl_credentials_get(&creds, "password"));
+    ASSERT_STREQ("username", wf_credentials_type(&creds));
+    ASSERT_STREQ(nullptr, wf_credentials_get(&creds, "username"));
+    ASSERT_STREQ(nullptr, wf_credentials_get(&creds, "password"));
 
     wf_impl_credentials_cleanup(&creds);
     json_decref(data);    
 }
 
+TEST(Credentials, FailedToGetWrongElementDataType)
+{
+    struct wf_credentials creds;
+    json_t * data = json_object();
+    json_object_set_new(data, "username", json_integer(42));
+
+    wf_impl_credentials_init(&creds, "username", data);
+    ASSERT_STREQ("username", wf_credentials_type(&creds));
+    ASSERT_STREQ(nullptr, wf_credentials_get(&creds, "username"));
+    ASSERT_STREQ(nullptr, wf_credentials_get(&creds, "password"));
+
+    wf_impl_credentials_cleanup(&creds);
+    json_decref(data);    
+}