diff --git a/impl/test/test_ham64.c b/impl/test/test_ham64.c
index 96945d7..31dc223 100644
--- a/impl/test/test_ham64.c
+++ b/impl/test/test_ham64.c
@@ -1,13 +1,13 @@
+#include <assert.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
-#include <stdbool.h>
 
 #include <layer2/ham64.h>
 
-bool test_decode(const char *ref, const ham64_t *ham64)
+bool test_decode(const char *ref, const char *exp_fmt, const char *exp_type, const ham64_t *ham64)
 {
-	char decoded[13];
-	decoded[12] = 0;
+	char decoded[13] = {0};
 
 	char ham64_format_buf[HAM64_FMT_MAX_LEN];
 
@@ -17,15 +17,17 @@ bool test_decode(const char *ref, const ham64_t *ham64)
 	const char *typestr = ham64_addr_type_to_string(ham64_get_addr_type(ham64));
 	printf("»%s« → [%u] %s (%s) → [%zd] »%s«\n", ref, ham64->length, ham64_format_buf, typestr, decoded_len, decoded);
 
-	return strcmp(ref, decoded) == 0;
+	return strcmp(ref, decoded) == 0
+		&& strcmp(exp_fmt, ham64_format_buf) == 0
+		&& strcmp(exp_type, typestr) == 0;
 }
 
-bool test_call(const char *call)
+bool test_call(const char *call, const char *exp_fmt)
 {
 	ham64_t ham64;
 
 	ham64_encode(call, &ham64);
-	return test_decode(call, &ham64);
+	return test_decode(call, exp_fmt, "CALLSIGN", &ham64);
 }
 
 int main(void)
@@ -39,12 +41,12 @@ int main(void)
 	ham64_t short_last = {{0x063F, 0x0, 0x0, 0x0}, 1};
 	ham64_t broadcast = {{0xFFFF, 0x0, 0x0, 0x0}, 1};
 
-	test_call(call1);
-	test_call(call2);
-	test_call(call3);
+	assert(test_call(call1, "8B05-0E89-7118-AEC8"));
+	assert(test_call(call2, "1B00-7EC4-EA60"));
+	assert(test_call(call3, "1EAB"));
 
-	test_decode("", &empty);
-	test_decode("", &short_1);
-	test_decode("", &short_last);
-	test_decode("", &broadcast);
+	assert(test_decode("", "0000", "EMPTY", &empty));
+	assert(test_decode("", "0001", "TMP_SHORT", &short_1));
+	assert(test_decode("", "063F", "TMP_SHORT", &short_last));
+	assert(test_decode("", "FFFF", "BROADCAST", &broadcast));
 }