diff --git a/test/test_runner.c b/test/test_runner.c
index d3440c5..56af24a 100644
--- a/test/test_runner.c
+++ b/test/test_runner.c
@@ -22,6 +22,7 @@ extern Suite *timers_suite(void);
 extern Suite *mbuf_suite(void);
 extern Suite *human_bytesz_suite(void);
 extern Suite *dbuf_suite(void);
+extern Suite *sprintb_suite(void);
 
 static suite_func suites[] = {
     bitvec_suite,
@@ -40,6 +41,7 @@ static suite_func suites[] = {
     mbuf_suite,
     human_bytesz_suite,
     dbuf_suite,
+    sprintb_suite
 };
 
 int
diff --git a/test/test_sprintb.c b/test/test_sprintb.c
new file mode 100644
index 0000000..0a1f782
--- /dev/null
+++ b/test/test_sprintb.c
@@ -0,0 +1,97 @@
+#include <check.h>
+#include <limits.h>
+#include <ucore/string.h>
+
+//Note these tests assume
+// char 8 bit
+// short 16 bit
+// int 32 bit
+// long long 64 bit
+
+START_TEST (test_sprintb)
+    char result[128];
+    char *rc;
+
+    rc = uc_sprintb(result, 0);
+    ck_assert_str_eq(rc, "00000000000000000000000000000000");
+
+    rc = uc_sprintb(result, UINT_MAX);
+    ck_assert_str_eq(rc, "11111111111111111111111111111111");
+
+    rc = uc_sprintb(result, 0xE0A14341);
+    ck_assert_str_eq(rc, "11100000101000010100001101000001");
+
+    rc = uc_sprintb(result, 1);
+    ck_assert_str_eq(rc, "00000000000000000000000000000001");
+
+END_TEST
+
+START_TEST (test_sprintbc)
+    char result[128];
+    char *rc;
+
+    rc = uc_sprintbc(result, 0);
+    ck_assert_str_eq(rc, "00000000");
+
+    rc = uc_sprintbc(result, UCHAR_MAX);
+    ck_assert_str_eq(rc, "11111111");
+
+    rc = uc_sprintbc(result, 0xE1);
+    ck_assert_str_eq(rc, "11100001");
+
+    rc = uc_sprintbc(result, 1);
+    ck_assert_str_eq(rc, "00000001");
+
+END_TEST
+
+START_TEST (test_sprintbs)
+    char result[128];
+    char *rc;
+
+    rc = uc_sprintbs(result, 0);
+    ck_assert_str_eq(rc, "0000000000000000");
+
+    rc = uc_sprintbs(result, USHRT_MAX);
+    ck_assert_str_eq(rc, "1111111111111111");
+
+    rc = uc_sprintbs(result, 0xE0A1);
+    ck_assert_str_eq(rc, "1110000010100001");
+
+    rc = uc_sprintbs(result, 1);
+    ck_assert_str_eq(rc, "0000000000000001");
+
+END_TEST
+
+START_TEST (test_sprintbll)
+    char result[128];
+    char *rc;
+
+    rc = uc_sprintbll(result, 0);
+    ck_assert_str_eq(rc, "0000000000000000000000000000000000000000000000000000000000000000");
+
+    rc = uc_sprintbll(result, ULLONG_MAX);
+    ck_assert_str_eq(rc, "1111111111111111111111111111111111111111111111111111111111111111");
+
+    rc = uc_sprintbll(result, 0xE0A14341E0A14341ULL);
+    ck_assert_str_eq(rc, "1110000010100001010000110100000111100000101000010100001101000001");
+
+    rc = uc_sprintbll(result, 1);
+    ck_assert_str_eq(rc, "0000000000000000000000000000000000000000000000000000000000000001");
+
+END_TEST
+
+Suite *sprintb_suite(void)
+{
+    Suite *s = suite_create("sprintb");
+    TCase *tc = tcase_create("sprintb tests");
+
+    tcase_add_test(tc, test_sprintb);
+    tcase_add_test(tc, test_sprintbc);
+    tcase_add_test(tc, test_sprintbs);
+    tcase_add_test(tc, test_sprintbll);
+
+    suite_add_tcase(s, tc);
+
+    return s;
+}
+