diff --git a/lib/m68020/descr b/lib/m68020/descr
index 49bd0a4fe..4b3a7a9bf 100644
--- a/lib/m68020/descr
+++ b/lib/m68020/descr
@@ -21,6 +21,15 @@ name be
 	stdout
 	need .e
 end
+name asopt
+	from .s
+	to .so
+	program {EM}/lib/{M}/top
+	args
+	optimizer
+	stdin
+	stdout
+end
 name as
 	from .s.so
 	to .o
diff --git a/lib/sun3/descr b/lib/sun3/descr
index 09a8ad263..57dbbaff3 100644
--- a/lib/sun3/descr
+++ b/lib/sun3/descr
@@ -25,6 +25,15 @@ name be
 	stdout
 	need .e
 end
+name asopt
+	from .s
+	to .so
+	program {EM}/lib/{M}/top
+	args
+	optimizer
+	stdin
+	stdout
+end
 name as
 	from .s.so
 	to .o