diff --git a/gen/x86_table.js b/gen/x86_table.js
index fdd12c51..aa92d5f6 100644
--- a/gen/x86_table.js
+++ b/gen/x86_table.js
@@ -203,8 +203,8 @@ const encodings = [
     { opcode: 0x99, os: 1, custom: 1 },
     { opcode: 0x9A, os: 1, imm1632: 1, extra_imm16: 1, skip: 1, block_boundary: 1, }, // callf
     { opcode: 0x9B, block_boundary: 1, skip: 1, }, // fwait: block_boundary since it uses non-raising cpu exceptions
-    { opcode: 0x9C, os: 1, custom: 1 },
-    { opcode: 0x9D, os: 1, skip: 1, custom: 1, },
+    { opcode: 0x9C, os: 1, custom: 1, skip: 1 }, // pushf
+    { opcode: 0x9D, os: 1, custom: 1, skip: 1 }, // popf
     { opcode: 0x9E, custom: 1 },
     { opcode: 0x9F, custom: 1 },
 
diff --git a/tests/nasm/pushf.asm b/tests/nasm/pushf.asm
new file mode 100644
index 00000000..692acd7e
--- /dev/null
+++ b/tests/nasm/pushf.asm
@@ -0,0 +1,12 @@
+global _start
+
+%include "header.inc"
+
+    pushf
+    and dword [esp], ~0x0200 ; if
+
+    db 66h
+    pushf
+    and dword [esp], ~0x0200
+
+%include "footer.inc"