diff --git a/dlls/ntdll/tests/file.c b/dlls/ntdll/tests/file.c
index 28287945f60..c1f1c48d26c 100644
--- a/dlls/ntdll/tests/file.c
+++ b/dlls/ntdll/tests/file.c
@@ -947,8 +947,11 @@ static void test_iocp_fileio(HANDLE h)
         ok( hPipeClt != INVALID_HANDLE_VALUE, "Cannot connect to pipe\n" );
         if (hPipeClt != INVALID_HANDLE_VALUE)
         {
+            U(iosb).Status = 0xdeadbeef;
             res = pNtSetInformationFile( hPipeSrv, &iosb, &fci, sizeof(fci), FileCompletionInformation );
             ok( res == STATUS_INVALID_PARAMETER, "Unexpected NtSetInformationFile on non-overlapped handle: %x\n", res );
+            ok( U(iosb).Status == STATUS_INVALID_PARAMETER /* 98 */ || U(iosb).Status == 0xdeadbeef /* NT4+ */,
+                "Unexpected iosb.Status on non-overlapped handle: %x\n", U(iosb).Status );
             CloseHandle(hPipeClt);
         }
         CloseHandle( hPipeSrv );
@@ -968,7 +971,8 @@ static void test_iocp_fileio(HANDLE h)
         DWORD read;
         long count;
 
-        NTSTATUS res = pNtSetInformationFile( hPipeSrv, &iosb, &fci, sizeof(fci), FileCompletionInformation );
+        U(iosb).Status = 0xdeadbeef;
+        res = pNtSetInformationFile( hPipeSrv, &iosb, &fci, sizeof(fci), FileCompletionInformation );
         ok( res == STATUS_SUCCESS, "NtSetInformationFile failed: %x\n", res );
         ok( U(iosb).Status == STATUS_SUCCESS, "iosb.Status invalid: %x\n", U(iosb).Status );
 
@@ -1047,8 +1051,10 @@ static void test_file_basic_information(void)
     /* Clear fbi to avoid setting times */
     memset(&fbi, 0, sizeof(fbi));
     fbi.FileAttributes = FILE_ATTRIBUTE_SYSTEM;
+    U(io).Status = 0xdeadbeef;
     res = pNtSetInformationFile(h, &io, &fbi, sizeof fbi, FileBasicInformation);
-    ok ( res == STATUS_SUCCESS, "can't set system attribute\n");
+    ok ( res == STATUS_SUCCESS, "can't set system attribute, NtSetInformationFile returned %x\n", res );
+    ok ( U(io).Status == STATUS_SUCCESS, "can't set system attribute, io.Status is %x\n", U(io).Status );
 
     memset(&fbi, 0, sizeof(fbi));
     res = pNtQueryInformationFile(h, &io, &fbi, sizeof fbi, FileBasicInformation);
@@ -1058,8 +1064,10 @@ static void test_file_basic_information(void)
     /* Then HIDDEN */
     memset(&fbi, 0, sizeof(fbi));
     fbi.FileAttributes = FILE_ATTRIBUTE_HIDDEN;
+    U(io).Status = 0xdeadbeef;
     res = pNtSetInformationFile(h, &io, &fbi, sizeof fbi, FileBasicInformation);
-    ok ( res == STATUS_SUCCESS, "can't set system attribute\n");
+    ok ( res == STATUS_SUCCESS, "can't set system attribute, NtSetInformationFile returned %x\n", res );
+    ok ( U(io).Status == STATUS_SUCCESS, "can't set system attribute, io.Status is %x\n", U(io).Status );
 
     memset(&fbi, 0, sizeof(fbi));
     res = pNtQueryInformationFile(h, &io, &fbi, sizeof fbi, FileBasicInformation);
@@ -1069,8 +1077,10 @@ static void test_file_basic_information(void)
     /* Check NORMAL last of all (to make sure we can clear attributes) */
     memset(&fbi, 0, sizeof(fbi));
     fbi.FileAttributes = FILE_ATTRIBUTE_NORMAL;
+    U(io).Status = 0xdeadbeef;
     res = pNtSetInformationFile(h, &io, &fbi, sizeof fbi, FileBasicInformation);
-    ok ( res == STATUS_SUCCESS, "can't set normal attribute\n");
+    ok ( res == STATUS_SUCCESS, "can't set normal attribute, NtSetInformationFile returned %x\n", res );
+    ok ( U(io).Status == STATUS_SUCCESS, "can't set normal attribute, io.Status is %x\n", U(io).Status );
 
     memset(&fbi, 0, sizeof(fbi));
     res = pNtQueryInformationFile(h, &io, &fbi, sizeof fbi, FileBasicInformation);
@@ -1107,10 +1117,14 @@ static void test_file_all_information(void)
     /* Clear fbi to avoid setting times */
     memset(&fai_buf.fai.BasicInformation, 0, sizeof(fai_buf.fai.BasicInformation));
     fai_buf.fai.BasicInformation.FileAttributes = FILE_ATTRIBUTE_SYSTEM;
+    U(io).Status = 0xdeadbeef;
     res = pNtSetInformationFile(h, &io, &fai_buf.fai, sizeof fai_buf, FileAllInformation);
-    ok ( res == STATUS_INVALID_INFO_CLASS || res == STATUS_NOT_IMPLEMENTED, "shouldn't be able to set FileAllInformation, res %x\n", res);
+    ok ( res == STATUS_INVALID_INFO_CLASS || broken(res == STATUS_NOT_IMPLEMENTED), "shouldn't be able to set FileAllInformation, res %x\n", res);
+    todo_wine ok ( U(io).Status == 0xdeadbeef, "shouldn't be able to set FileAllInformation, io.Status is %x\n", U(io).Status);
+    U(io).Status = 0xdeadbeef;
     res = pNtSetInformationFile(h, &io, &fai_buf.fai.BasicInformation, sizeof fai_buf.fai.BasicInformation, FileBasicInformation);
-    ok ( res == STATUS_SUCCESS, "can't set system attribute\n");
+    ok ( res == STATUS_SUCCESS, "can't set system attribute, res: %x\n", res );
+    ok ( U(io).Status == STATUS_SUCCESS, "can't set system attribute, io.Status: %x\n", U(io).Status );
 
     memset(&fai_buf.fai, 0, sizeof(fai_buf.fai));
     res = pNtQueryInformationFile(h, &io, &fai_buf.fai, sizeof fai_buf, FileAllInformation);
@@ -1120,8 +1134,10 @@ static void test_file_all_information(void)
     /* Then HIDDEN */
     memset(&fai_buf.fai.BasicInformation, 0, sizeof(fai_buf.fai.BasicInformation));
     fai_buf.fai.BasicInformation.FileAttributes = FILE_ATTRIBUTE_HIDDEN;
+    U(io).Status = 0xdeadbeef;
     res = pNtSetInformationFile(h, &io, &fai_buf.fai.BasicInformation, sizeof fai_buf.fai.BasicInformation, FileBasicInformation);
-    ok ( res == STATUS_SUCCESS, "can't set system attribute\n");
+    ok ( res == STATUS_SUCCESS, "can't set system attribute, res: %x\n", res );
+    ok ( U(io).Status == STATUS_SUCCESS, "can't set system attribute, io.Status: %x\n", U(io).Status );
 
     memset(&fai_buf.fai, 0, sizeof(fai_buf.fai));
     res = pNtQueryInformationFile(h, &io, &fai_buf.fai, sizeof fai_buf, FileAllInformation);
@@ -1131,8 +1147,10 @@ static void test_file_all_information(void)
     /* Check NORMAL last of all (to make sure we can clear attributes) */
     memset(&fai_buf.fai.BasicInformation, 0, sizeof(fai_buf.fai.BasicInformation));
     fai_buf.fai.BasicInformation.FileAttributes = FILE_ATTRIBUTE_NORMAL;
+    U(io).Status = 0xdeadbeef;
     res = pNtSetInformationFile(h, &io, &fai_buf.fai.BasicInformation, sizeof fai_buf.fai.BasicInformation, FileBasicInformation);
-    ok ( res == STATUS_SUCCESS, "can't set normal attribute\n");
+    ok ( res == STATUS_SUCCESS, "can't set system attribute, res: %x\n", res );
+    ok ( U(io).Status == STATUS_SUCCESS, "can't set system attribute, io.Status: %x\n", U(io).Status );
 
     memset(&fai_buf.fai, 0, sizeof(fai_buf.fai));
     res = pNtQueryInformationFile(h, &io, &fai_buf.fai, sizeof fai_buf, FileAllInformation);