diff --git a/src/Makefile b/src/Makefile
index a088f55..0983d58 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -86,10 +86,7 @@ streamReferences: ../CONFIG_STREAM
 
 # create stream.dbd from all RECORDTYPES
 $(COMMON_DIR)/$(LIBRARY_DEFAULT).dbd: ../CONFIG_STREAM
-	$(PERL) ../makedbd.pl $(RECORDTYPES) > $@
-ifdef ASYN
-	echo "registrar(AsynDriverInterfaceRegistrar)" >> $@
-endif
+	$(PERL) ../makedbd.pl $(if $(ASYN),--with-asyn) $(if $(BASE_3_14),,-3.13) $(RECORDTYPES) > $@
 
 $(LIBRARY_DEFAULT).dbd$(DEP): ../CONFIG_STREAM
 	echo $(LIBRARY_DEFAULT).dbd: $< > $@
diff --git a/src/makedbd.pl b/src/makedbd.pl
index 97ba29e..b9757cb 100644
--- a/src/makedbd.pl
+++ b/src/makedbd.pl
@@ -1,9 +1,14 @@
-if (@ARGV[0] == "-3.13") {
+if (@ARGV[0] eq "--with-asyn") {
+    shift;
+    $asyn = 1;
+}
+if (@ARGV[0] eq "-3.13") {
     shift;
 } else {
     print "variable(streamDebug, int)\n";
     print "variable(streamError, int)\n";
     print "registrar(streamRegistrar)\n";
+    if ($asyn) { print "registrar(AsynDriverInterfaceRegistrar)\n"; }
 }
 print "driver(stream)\n";
 for (@ARGV) {