diff --git a/pdpasmhelper.py b/pdpasmhelper.py
index 3793e25..bb84c5e 100644
--- a/pdpasmhelper.py
+++ b/pdpasmhelper.py
@@ -247,6 +247,9 @@ class PDP11InstructionAssembler:
     def negb(self, dst):
         return self._1op(0o105400, dst)
 
+    def adc(self, dst):
+        return self._1op(0o005500, dst)
+
     def tst(self, dst):
         return self._1op(0o005700, dst)