diff --git a/dlls/kernel32/tests/process.c b/dlls/kernel32/tests/process.c
index b0371c615e6573ea594bec54c035191bb6ad744c..8996dd914462fcb5b11b4b2c2361d26ccba538ad 100644
--- a/dlls/kernel32/tests/process.c
+++ b/dlls/kernel32/tests/process.c
@@ -3685,7 +3685,7 @@ static void test_process_info(HANDLE hproc)
         case ProcessPriorityClass:
         case ProcessPriorityBoost:
         case ProcessLUIDDeviceMapsEnabled:
-        case 33 /* ProcessIoPriority */:
+        case ProcessIoPriority:
         case ProcessIoCounters:
         case ProcessVmCounters:
         case ProcessWow64Information:
diff --git a/include/winternl.h b/include/winternl.h
index e23a02b9b263f13784db7bd826ebe673bb5b83c7..20b2a44ba2030d6cdb0ee6a5dc561fe7037eca4f 100644
--- a/include/winternl.h
+++ b/include/winternl.h
@@ -1153,6 +1153,7 @@ typedef enum _PROCESSINFOCLASS {
     ProcessDebugObjectHandle = 30,
     ProcessDebugFlags = 31,
     ProcessHandleTracing = 32,
+    ProcessIoPriority = 33,
     ProcessExecuteFlags = 34,
     ProcessTlsInformation = 35,
     ProcessCookie = 36,