diff --git a/GNUmakefile b/GNUmakefile
index d52646d..0d30e88 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -17,6 +17,7 @@
 PREFIX=/usr/local
 CC=cc
 CFLAGS=-O3 -Lbuild/lib
+RUSTC=rustc
 
 ifeq ($(CC), gcc)
 	CFLAGS=-O3 -s -Wl,-z,noseparate-code,-z,nosectionheader -flto \
@@ -51,8 +52,8 @@ test: build
 	tests/cc-compat.sh
 	tests/posix-compat.sh
 
-false: src/false.c build_dir
-	$(CC) $(CFLAGS) -o build/bin/false src/false.c
+false: src/false.rs build_dir
+	$(RUSTC) -o build/bin/false src/false.rs
 
 intcmp: src/intcmp.c build_dir
 	$(CC) $(CFLAGS) -o build/bin/intcmp src/intcmp.c