1 files changed, 7 insertions, 1 deletions
diff --git a/chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala b/chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala
index b7fd65a5..c40b85ad 100644
--- a/chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala
+++ b/chiselFrontend/src/main/scala/chisel3/core/BiConnect.scala
@@ -188,7 +188,13 @@ object BiConnect {
             throw BothDriversException
           }
         }
-        case (None,         None)         => throw UnknownDriverException
+        case (None,         None)         => {
+          if (compileOptions.assumeLHSIsOutput) {
+            issueConnectR2L(left, right)
+          } else {
+            throw UnknownDriverException
+          }
+        }
       }
     }