diff --git a/decode.c b/decode.c
index 8e81238..66f17db 100644
--- a/decode.c
+++ b/decode.c
@@ -396,15 +396,6 @@ fd_decode(const uint8_t* buffer, size_t len_sz, int mode_int, uintptr_t address,
     if (LIKELY(off < len))
         ENTRY_UNPACK(table, kind, table[buffer[off++]]);
 
-    // Then, walk through ModR/M-encoded opcode extensions.
-    if ((kind == ENTRY_TABLE8 || kind == ENTRY_TABLE72) && LIKELY(off < len))
-    {
-        if (kind == ENTRY_TABLE72 && (buffer[off] & 0xc0) == 0xc0)
-            ENTRY_UNPACK(table, kind, table[buffer[off++] - 0xb8]);
-        else
-            ENTRY_UNPACK(table, kind, table[(buffer[off] >> 3) & 7]);
-    }
-
     // Handle mandatory prefixes (which behave like an opcode ext.).
     if (kind == ENTRY_TABLE_PREFIX)
     {
@@ -417,6 +408,15 @@ fd_decode(const uint8_t* buffer, size_t len_sz, int mode_int, uintptr_t address,
         ENTRY_UNPACK(table, kind, table[mandatory_prefix]);
     }
 
+    // Then, walk through ModR/M-encoded opcode extensions.
+    if ((kind == ENTRY_TABLE8 || kind == ENTRY_TABLE72) && LIKELY(off < len))
+    {
+        if (kind == ENTRY_TABLE72 && (buffer[off] & 0xc0) == 0xc0)
+            ENTRY_UNPACK(table, kind, table[buffer[off++] - 0xb8]);
+        else
+            ENTRY_UNPACK(table, kind, table[(buffer[off] >> 3) & 7]);
+    }
+
     // For VEX prefix, we have to distinguish between VEX.W and VEX.L which may
     // be part of the opcode.
     if (kind == ENTRY_TABLE_VEX)
diff --git a/parseinstrs.py b/parseinstrs.py
index 12324c8..7ac0847 100644
--- a/parseinstrs.py
+++ b/parseinstrs.py
@@ -288,6 +288,12 @@ class Opcode(NamedTuple):
         opcode = []
         opcode.append((EntryKind.TABLE_ROOT, [self.escape | self.vex << 2]))
         opcode.append((EntryKind.TABLE256, [self.opc]))
+        if self.prefix:
+            if self.prefix == "NFx":
+                opcode.append((EntryKind.TABLE_PREFIX, [0, 1]))
+            else:
+                prefix_val = ["NP", "66", "F3", "F2"].index(self.prefix)
+                opcode.append((EntryKind.TABLE_PREFIX, [prefix_val]))
         if self.opcext:
             opcext_kind = [EntryKind.TABLE8, EntryKind.TABLE72][self.opcext[0]]
             opcext_val = self.opcext[1] - (0 if self.opcext[1] < 8 else 0xb8)
@@ -295,12 +301,6 @@ class Opcode(NamedTuple):
         if self.extended:
             last_type, last_indices = opcode[-1]
             opcode[-1] = last_type, [last_indices[0] + i for i in range(8)]
-        if self.prefix:
-            if self.prefix == "NFx":
-                opcode.append((EntryKind.TABLE_PREFIX, [0, 1]))
-            else:
-                prefix_val = ["NP", "66", "F3", "F2"].index(self.prefix)
-                opcode.append((EntryKind.TABLE_PREFIX, [prefix_val]))
         if self.vexl in ("0", "1") or self.rexw in ("0", "1"):
             rexw = {"0": [0], "1": [1<<0], "IG": [0, 1<<0]}[self.rexw or "IG"]
             vexl = {"0": [0], "1": [1<<1], "IG": [0, 1<<1]}[self.vexl or "IG"]