diff --git a/contrib/40.procedure/nitro.mk b/contrib/40.procedure/nitro.mk
new file mode 100644
index 00000000..e19a0b68
--- /dev/null
+++ b/contrib/40.procedure/nitro.mk
@@ -0,0 +1 @@
+CONTRIB_LIBS += $(wildcard contrib/40.procedure/*.scm)
diff --git a/contrib/50.procedure/procedure.scm b/contrib/40.procedure/procedure.scm
similarity index 100%
rename from contrib/50.procedure/procedure.scm
rename to contrib/40.procedure/procedure.scm
diff --git a/contrib/50.procedure/nitro.mk b/contrib/50.procedure/nitro.mk
deleted file mode 100644
index 87f2e8f5..00000000
--- a/contrib/50.procedure/nitro.mk
+++ /dev/null
@@ -1 +0,0 @@
-CONTRIB_LIBS += $(wildcard contrib/50.procedure/*.scm)