diff --git a/base/system/smss/pagefile.c b/base/system/smss/pagefile.c
index bd4df1a5c9f..6af9b214951 100644
--- a/base/system/smss/pagefile.c
+++ b/base/system/smss/pagefile.c
@@ -837,8 +837,8 @@ SmpCreateVolumeDescriptors(VOID)
     /* Query the device map so we can get the drive letters */
     Status = NtQueryInformationProcess(NtCurrentProcess(),
                                        ProcessDeviceMap,
-                                       &ProcessInformation,
-                                       sizeof(ProcessInformation),
+                                       &ProcessInformation.Query,
+                                       sizeof(ProcessInformation.Query),
                                        NULL);
     if (!NT_SUCCESS(Status))
     {
diff --git a/dll/win32/kernel32/client/file/disk.c b/dll/win32/kernel32/client/file/disk.c
index 7fe80616662..12751c6b1ad 100644
--- a/dll/win32/kernel32/client/file/disk.c
+++ b/dll/win32/kernel32/client/file/disk.c
@@ -115,8 +115,8 @@ GetLogicalDrives(VOID)
     /* Get the Device Map for this Process */
     Status = NtQueryInformationProcess(NtCurrentProcess(),
                                        ProcessDeviceMap,
-                                       &ProcessDeviceMapInfo,
-                                       sizeof(ProcessDeviceMapInfo),
+                                       &ProcessDeviceMapInfo.Query,
+                                       sizeof(ProcessDeviceMapInfo.Query),
                                        NULL);
 
     /* Return the Drive Map */
@@ -557,9 +557,10 @@ GetDriveTypeW(IN LPCWSTR lpRootPathName)
         PROCESS_DEVICEMAP_INFORMATION DeviceMap;
 
         /* Query the device map */
-        Status = NtQueryInformationProcess(NtCurrentProcess(), ProcessDeviceMap,
-                                           &DeviceMap,
-                                           sizeof(PROCESS_DEVICEMAP_INFORMATION),
+        Status = NtQueryInformationProcess(NtCurrentProcess(),
+                                           ProcessDeviceMap,
+                                           &DeviceMap.Query,
+                                           sizeof(DeviceMap.Query),
                                            NULL);
         /* Zero output if we failed */
         if (!NT_SUCCESS(Status))
diff --git a/ntoskrnl/ps/query.c b/ntoskrnl/ps/query.c
index 7a1767d54ff..1f605be3349 100644
--- a/ntoskrnl/ps/query.c
+++ b/ntoskrnl/ps/query.c
@@ -564,7 +564,7 @@ NtQueryInformationProcess(IN HANDLE ProcessHandle,
         /* DOS Device Map */
         case ProcessDeviceMap:
 
-            if (ProcessInformationLength != sizeof(PROCESS_DEVICEMAP_INFORMATION))
+            if (ProcessInformationLength != RTL_FIELD_SIZE(PROCESS_DEVICEMAP_INFORMATION, Query))
             {
                 if (ProcessInformationLength == sizeof(PROCESS_DEVICEMAP_INFORMATION_EX))
                 {