diff --git a/include/security/oath.h b/include/security/oath.h
index e897162..7dfed25 100644
--- a/include/security/oath.h
+++ b/include/security/oath.h
@@ -42,10 +42,6 @@ struct oath_key *oath_key_from_uri(const char *);
 struct oath_key *oath_key_from_file(const char *);
 char *oath_key_to_uri(const struct oath_key *);
 
-#define DUMMY_LABEL	("oath-dummy-key")
-#define DUMMY_LABELLEN	(sizeof DUMMY_LABEL)
-#define DUMMY_KEYLEN	64
-
 struct oath_key *oath_dummy_key(enum oath_mode, enum oath_hash, unsigned int);
 
 unsigned int oath_hotp(const uint8_t *, size_t, uint64_t, unsigned int);
diff --git a/include/security/oath_constants.h b/include/security/oath_constants.h
index 1838d61..465c64c 100644
--- a/include/security/oath_constants.h
+++ b/include/security/oath_constants.h
@@ -76,4 +76,9 @@ enum oath_hash {
  */
 #define OATH_MAX_LABELLEN	64
 
+/*
+ * Label to use for dummy keys
+ */
+#define OATH_DUMMY_LABEL	"oath-dummy-key"
+
 #endif
diff --git a/lib/liboath/oath_hotp.c b/lib/liboath/oath_hotp.c
index 9642f9e..28d0d63 100644
--- a/lib/liboath/oath_hotp.c
+++ b/lib/liboath/oath_hotp.c
@@ -127,7 +127,7 @@ oath_hotp_match(struct oath_key *k, unsigned int response, int window)
 		return (-1);
 	if (k->counter >= UINT64_MAX - window)
 		return (-1);
-	dummy = (memcmp(k->label, DUMMY_LABEL, DUMMY_LABELLEN) == 0);
+	dummy = (strcmp(k->label, OATH_DUMMY_LABEL) == 0);
 	for (int i = 0; i < window; ++i) {
 		code = oath_hotp(k->key, k->keylen, k->counter + i, k->digits);
 		if (code == response && !dummy) {
diff --git a/lib/liboath/oath_key.c b/lib/liboath/oath_key.c
index 98ff3dc..45878bd 100644
--- a/lib/liboath/oath_key.c
+++ b/lib/liboath/oath_key.c
@@ -310,8 +310,8 @@ oath_dummy_key(enum oath_mode mode, enum oath_hash hash, unsigned int digits)
 	key->counter = 0;
 	key->timestep = 30;
 	key->hash = hash;
-	memcpy(key->label, DUMMY_LABEL, DUMMY_LABELLEN);
-	key->labellen = DUMMY_LABELLEN;
-	key->keylen = DUMMY_KEYLEN;
+	strcpy(key->label, "oath-dummy-key");
+	key->labellen = strlen(key->label);
+	key->keylen = sizeof key->key;
 	return (key);
 }
diff --git a/lib/liboath/oath_totp.c b/lib/liboath/oath_totp.c
index f21b21a..4c3e2c4 100644
--- a/lib/liboath/oath_totp.c
+++ b/lib/liboath/oath_totp.c
@@ -83,7 +83,7 @@ oath_totp_match(const struct oath_key *k, unsigned int response, int window)
 	if (k->timestep == 0)
 		return (-1);
 	seq = time(NULL) / k->timestep;
-	dummy = (memcmp(k->label, DUMMY_LABEL, DUMMY_LABELLEN) == 0);
+	dummy = (strcmp(k->label, OATH_DUMMY_LABEL) == 0);
 	for (int i = -window; i <= window; ++i) {
 		code = oath_hotp(k->key, k->keylen, seq + i, k->digits);
 		if (code == response && !dummy)