diff --git a/Makefile b/Makefile
index fc7345a..2856c85 100644
--- a/Makefile
+++ b/Makefile
@@ -92,7 +92,8 @@ ifeq ($(shell rustup component list --toolchain=nightly \
 	rustup component add --toolchain=nightly rust-src
 endif
 endif
-	cargo $(if $(call eq,$(careful),yes),+nightly careful,) test --all-features
+	cargo $(if $(call eq,$(careful),yes),+nightly careful,) test --all-features\
+		$(if $(call eq,$(careful),yes),--lib,)