diff --git a/reactos/include/psdk/psapi.h b/reactos/include/psdk/psapi.h
index 15c9df54651..886f5a86384 100644
--- a/reactos/include/psdk/psapi.h
+++ b/reactos/include/psdk/psapi.h
@@ -37,15 +37,29 @@ typedef struct _PSAPI_WS_WATCH_INFORMATION {
 typedef struct _PROCESS_MEMORY_COUNTERS {
 	DWORD cb;
 	DWORD PageFaultCount;
-	DWORD PeakWorkingSetSize;
-	DWORD WorkingSetSize;
-	DWORD QuotaPeakPagedPoolUsage;
-	DWORD QuotaPagedPoolUsage;
-	DWORD QuotaPeakNonPagedPoolUsage;
-	DWORD QuotaNonPagedPoolUsage;
-	DWORD PagefileUsage;
-	DWORD PeakPagefileUsage;
-} PROCESS_MEMORY_COUNTERS,*PPROCESS_MEMORY_COUNTERS;
+	SIZE_T PeakWorkingSetSize;
+	SIZE_T WorkingSetSize;
+	SIZE_T QuotaPeakPagedPoolUsage;
+	SIZE_T QuotaPagedPoolUsage;
+	SIZE_T QuotaPeakNonPagedPoolUsage;
+	SIZE_T QuotaNonPagedPoolUsage;
+	SIZE_T PagefileUsage;
+	SIZE_T PeakPagefileUsage;
+} PROCESS_MEMORY_COUNTERS, *PPROCESS_MEMORY_COUNTERS;
+
+typedef struct _PROCESS_MEMORY_COUNTERS_EX {
+	DWORD cb;
+	DWORD PageFaultCount;
+	SIZE_T PeakWorkingSetSize;
+	SIZE_T WorkingSetSize;
+	SIZE_T QuotaPeakPagedPoolUsage;
+	SIZE_T QuotaPagedPoolUsage;
+	SIZE_T QuotaPeakNonPagedPoolUsage;
+	SIZE_T QuotaNonPagedPoolUsage;
+	SIZE_T PagefileUsage;
+	SIZE_T PeakPagefileUsage;
+	SIZE_T PrivateUsage;
+} PROCESS_MEMORY_COUNTERS_EX, *PPROCESS_MEMORY_COUNTERS_EX;
 
 typedef struct _PERFORMANCE_INFORMATION {
 	DWORD cb;