diff --git a/rules.mk b/rules.mk
index dacaa6b..49b9edd 100644
--- a/rules.mk
+++ b/rules.mk
@@ -16,8 +16,8 @@
 	--cfg 'feature="default"'
 
 MODULE_LIBRARY_DEPS := \
-	external/rust/crates/bit_field \
-	external/rust/crates/log \
+	$(call FIND_CRATE,bit_field) \
+	$(call FIND_CRATE,log) \
 	trusty/user/base/lib/libcompiler_builtins-rust \
 	trusty/user/base/lib/libcore-rust \
 	trusty/user/base/lib/liballoc-rust \