diff --git a/vm/in/instrs.h b/vm/in/instrs.h
index 7c3a9b3..6a88eba 100644
--- a/vm/in/instrs.h
+++ b/vm/in/instrs.h
@@ -68,7 +68,7 @@ bool i_##name(ctx_t *ctx, acc_t *p1, acc_t *p2, ulong *r1, ulong *r2)       \
 
 #define CHK_SUPERV()                                                        \
     do {                                                                    \
-        if ((cr0 & UF) == 1) {                                              \
+        if ((cr0 & UF) > 0) {                                               \
             _except(ctx, E_SYS, "Supervisor-only INSTR");                   \
         }                                                                   \
     } while (0)
diff --git a/vm/pc/regs.h b/vm/pc/regs.h
index 7dde844..9858c6c 100644
--- a/vm/pc/regs.h
+++ b/vm/pc/regs.h
@@ -1,6 +1,46 @@
 // The OS/K Team licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+// Register types
+enum
+{
+    GPR = 1 << 0,   // General
+    CTL = 1 << 1,   // Control
+    SEG = 1 << 2,   // Segment
+    RES = 1 << 8,   // Reserved for insternal use
+    SYS = 1 << 9,   // Reserved for supervisor mode
+};
+
+// FLG register
+enum
+{
+    CF = 1 << 0,        // Carry flag
+    OF = 1 << 1,        // Overflow flag
+
+    ZF = 1 << 2,        // Zero flag
+    SF = 1 << 3,        // Sign flag
+
+    PF = 1 << 4,        // Parity flag
+    DF = 1 << 5,        // Direction flag
+
+    IF = 1 << 16,       // Interrupts enable flag
+};
+
+// CR0 register
+enum
+{
+    UF = 1 << 15,       // User-mode flag
+};
+
+struct reg_t
+{
+    char   *name;
+    char   *desc;
+    char   *conv;
+    ulong   val;
+    ulong   flags;
+};
+
 enum
 {
     INV,
@@ -71,37 +111,4 @@ enum
     NREGS
 };
 
-enum
-{
-    GPR = 1 << 0,   // General
-    CTL = 1 << 1,   // Control
-    SEG = 1 << 2,   // Segment
-    RES = 1 << 8,   // Reserved for insternal use
-    SYS = 1 << 9,   // Reserved for supervisor mode
-};
-
-// FLG register
-enum
-{
-    CF = 1 << 0,        // Carry flag
-    OF = 1 << 1,        // Overflow flag
-
-    ZF = 1 << 2,        // Zero flag
-    SF = 1 << 3,        // Sign flag
-
-    PF = 1 << 4,        // Parity flag
-    DF = 1 << 5,        // Direction flag
-
-    UF = 1 << 16,       // User-mode flag
-    IF = 1 << 17,       // Interrupts enable flag
-};
-
-struct reg_t
-{
-    char   *name;
-    char   *desc;
-    char   *conv;
-    ulong   val;
-    ulong   flags;
-};