diff --git a/klibc/Makefile b/klibc/Makefile
index 588c0c7..96dff99 100644
--- a/klibc/Makefile
+++ b/klibc/Makefile
@@ -56,6 +56,12 @@
 tests/%.o : tests/%.c
 	$(CC) $(CFLAGS) -c -o $@ $<
 
+# This particular file uses a bunch of formats gcc don't know of, in order
+# to test the full range of our vsnprintf() function.  This outputs a bunch
+# of useless warnings unless we tell it not to.
+tests/testvsnp.o : tests/testvsnp.c
+	$(CC) $(CFLAGS) -Wno-format -c -o $@ $<
+
 tests/% : tests/%.o $(LIB) $(CRT0)
 	$(LD) $(LDFLAGS) -o $@ $(CRT0) $< $(LIB) $(LIBGCC)
 	cp $@ $@.stripped