diff --git a/src/arch/x86/isa/microasm.isa b/src/arch/x86/isa/microasm.isa
index 0cc72bf7b..c6f5e9cdd 100644
--- a/src/arch/x86/isa/microasm.isa
+++ b/src/arch/x86/isa/microasm.isa
@@ -151,6 +151,10 @@ let {{
         assembler.symbols["r%s" % reg] = \
             regIdx("INTREG_R%s" % reg.upper())
 
+    for reg in ('ah', 'bh', 'ch', 'dh'):
+        assembler.symbols[reg] = \
+            regIdx("INTREG_FOLDED(INTREG_%s, IntFoldBit)" % reg.upper())
+
     for reg in range(16):
         assembler.symbols["cr%d" % reg] = regIdx("MISCREG_CR%d" % reg)