diff --git a/Makefile b/Makefile
index c946aa23c96f269a9c29cd159f0a1cbafaf9f91f..f277b359bd51348378af44291159c31e86b7c7be 100644
--- a/Makefile
+++ b/Makefile
@@ -21,6 +21,10 @@ ifdef ASDF_TEST_SYSTEMS
 s ?= ${ASDF_TEST_SYSTEMS}
 endif
 
+ifdef ASDF_DEVEL_SOURCE_REGISTRY
+CL_SOURCE_REGISTRY = ${ASDF_DEVEL_SOURCE_REGISTRY}
+endif
+
 l ?= sbcl
 
 ABCL ?= abcl