diff --git a/reactos/include/defines.h b/reactos/include/defines.h
index cab5cc3683b..f7afb23bab0 100644
--- a/reactos/include/defines.h
+++ b/reactos/include/defines.h
@@ -4751,6 +4751,38 @@ typedef enum _SC_ENUM_TYPE {
 
 #endif /* !__USE_W32API */
 
+typedef enum _SystemState {
+  STATE_SYSTEM_UNAVAILABLE        = 0x00000001, // Disabled
+  STATE_SYSTEM_SELECTED           = 0x00000002,
+  STATE_SYSTEM_FOCUSED            = 0x00000004,
+  STATE_SYSTEM_PRESSED            = 0x00000008,
+  STATE_SYSTEM_CHECKED            = 0x00000010,
+  STATE_SYSTEM_MIXED              = 0x00000020, // 3-state checkbox or toolbar button
+  STATE_SYSTEM_READONLY           = 0x00000040,
+  STATE_SYSTEM_HOTTRACKED         = 0x00000080,
+  STATE_SYSTEM_DEFAULT            = 0x00000100,
+  STATE_SYSTEM_EXPANDED           = 0x00000200,
+  STATE_SYSTEM_COLLAPSED          = 0x00000400,
+  STATE_SYSTEM_BUSY               = 0x00000800,
+  STATE_SYSTEM_FLOATING           = 0x00001000, // Children "owned" not "contained" by parent
+  STATE_SYSTEM_MARQUEED           = 0x00002000,
+  STATE_SYSTEM_ANIMATED           = 0x00004000,
+  STATE_SYSTEM_INVISIBLE          = 0x00008000,
+  STATE_SYSTEM_OFFSCREEN          = 0x00010000,
+  STATE_SYSTEM_SIZEABLE           = 0x00020000,
+  STATE_SYSTEM_MOVEABLE           = 0x00040000,
+  STATE_SYSTEM_SELFVOICING        = 0x00080000,
+  STATE_SYSTEM_FOCUSABLE          = 0x00100000,
+  STATE_SYSTEM_SELECTABLE         = 0x00200000,
+  STATE_SYSTEM_LINKED             = 0x00400000,
+  STATE_SYSTEM_TRAVERSED          = 0x00800000,
+  STATE_SYSTEM_MULTISELECTABLE    = 0x01000000,  // Supports multiple selection
+  STATE_SYSTEM_EXTSELECTABLE      = 0x02000000,  // Supports extended selection
+  STATE_SYSTEM_ALERT_LOW          = 0x04000000,  // This information is of low priority
+  STATE_SYSTEM_ALERT_MEDIUM       = 0x08000000,  // This information is of medium priority
+  STATE_SYSTEM_ALERT_HIGH         = 0x10000000,  // This information is of high priority
+  STATE_SYSTEM_VALID              = 0x1FFFFFFF
+} SystemState;
 
 #ifdef __cplusplus
 }