diff --git a/src/tests/Makefile b/src/tests/Makefile
new file mode 100644
index 0000000..4722d2d
--- /dev/null
+++ b/src/tests/Makefile
@@ -0,0 +1,9 @@
+
+PKG_INCLUDES:=$(shell pkg-config --cflags libosmocore libosmovty libosmogsm libasn1c)
+PKG_LDFLAGS:=$(shell pkg-config --libs libosmocore libosmovty libosmogsm libasn1c)
+
+CFLAGS:=-g -Wall $(PKG_INCLUDES) -I..
+LDFLAGS:=$(PKG_LDFLAGS)
+
+test-helpers: ../iu_helpers.o test-helpers.c
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $^
diff --git a/src/tests/test-helpers.c b/src/tests/test-helpers.c
new file mode 100644
index 0000000..e23f017
--- /dev/null
+++ b/src/tests/test-helpers.c
@@ -0,0 +1,35 @@
+#include "iu_helpers.h"
+#include "asn1helpers.h"
+
+#include <assert.h>
+#define ASSERT(x)	assert(x)
+
+#include <osmocom/core/utils.h>
+
+void *talloc_asn1_ctx;
+
+/* use odd number of digits */
+const uint8_t imsi_encoded[] = { 0x10, 0x32, 0x54, 0x76, 0xF8 };
+const char imsi_decoded[] = "012345678";
+
+int main(int argc, char **argv)
+{
+	char outstr[32];
+	uint8_t outbuf[16];
+	int rc;
+
+	printf("pre-encoded: %s\n", osmo_hexdump_nospc(imsi_encoded,
+						sizeof(imsi_encoded)));
+	rc = decode_iu_bcd(outstr, sizeof(outstr), imsi_encoded,
+			   sizeof(imsi_encoded));
+	ASSERT(rc >= 0);
+	printf("decoded: %s\n", outstr);
+	ASSERT(!strcmp(outstr, imsi_decoded));
+
+	rc = encode_iu_imsi(outbuf, sizeof(outbuf), imsi_decoded);
+	ASSERT(rc >= 0);
+	printf("re-encoded: %s\n", osmo_hexdump_nospc(outbuf, rc));
+	ASSERT(!memcmp(outbuf, imsi_encoded, sizeof(imsi_encoded)));
+
+	return 0;
+}