diff --git a/Makefile b/Makefile
index 70ab13c..09110e3 100644
--- a/Makefile
+++ b/Makefile
@@ -120,8 +120,8 @@ build/bin/scrut: src/scrut.c build
 
 .PHONY: sleep
 sleep: build/bin/sleep
-build/bin/sleep: src/sleep.rs build
-	$(RUSTC) $(RUSTFLAGS)
+build/bin/sleep: src/sleep.rs build rustlibs
+	$(RUSTC) $(RUSTFLAGS) \
 		--extern sysexits=build/o/libsysexits.rlib \
 		-o $@ src/sleep.rs