diff --git a/src/libopensc/dir.c b/src/libopensc/dir.c
index b6c9b646..895ad65a 100644
--- a/src/libopensc/dir.c
+++ b/src/libopensc/dir.c
@@ -65,12 +65,13 @@ parse_dir_record(sc_card_t *card, u8 ** buf, size_t *buflen, int rec_nr)
 	sc_app_info_t *app = NULL;
 	struct sc_aid aid;
 	u8 label[128], path[128], ddo[128];
-	size_t label_len = sizeof(label), path_len = sizeof(path), ddo_len = sizeof(ddo);
+	size_t label_len = sizeof(label) - 1, path_len = sizeof(path), ddo_len = sizeof(ddo);
 	int r;
 
 	LOG_FUNC_CALLED(ctx);
 	aid.len = sizeof(aid.value);
 
+	memset(label, 0, sizeof(label));
 	sc_copy_asn1_entry(c_asn1_dirrecord, asn1_dirrecord);
 	sc_copy_asn1_entry(c_asn1_dir, asn1_dir);
 	sc_format_asn1_entry(asn1_dir + 0, asn1_dirrecord, NULL, 0);
diff --git a/src/libopensc/pkcs15-data.c b/src/libopensc/pkcs15-data.c
index b87ef584..636968ac 100644
--- a/src/libopensc/pkcs15-data.c
+++ b/src/libopensc/pkcs15-data.c
@@ -100,9 +100,11 @@ int sc_pkcs15_decode_dodf_entry(struct sc_pkcs15_card *p15card,
 				asn1_data[2];
 	struct sc_asn1_pkcs15_object data_obj = { obj, asn1_com_data_attr, NULL,
 					     asn1_type_data_attr };
-	size_t label_len = sizeof(info.app_label);
+	size_t label_len = sizeof(info.app_label) - 1;
 	int r;
 
+	memset(info.app_label, 0, sizeof(info.app_label));
+
 	sc_copy_asn1_entry(c_asn1_com_data_attr, asn1_com_data_attr);
 	sc_copy_asn1_entry(c_asn1_type_data_attr, asn1_type_data_attr);
 	sc_copy_asn1_entry(c_asn1_data, asn1_data);
diff --git a/src/libopensc/pkcs15.c b/src/libopensc/pkcs15.c
index 823b236b..85e7ecc7 100644
--- a/src/libopensc/pkcs15.c
+++ b/src/libopensc/pkcs15.c
@@ -131,9 +131,9 @@ int sc_pkcs15_parse_tokeninfo(sc_context_t *ctx,
 	u8 serial[128];
 	size_t serial_len = sizeof(serial);
 	u8 mnfid[SC_PKCS15_MAX_LABEL_SIZE];
-	size_t mnfid_len  = sizeof(mnfid);
+	size_t mnfid_len  = sizeof(mnfid) - 1;
 	u8 label[SC_PKCS15_MAX_LABEL_SIZE];
-	size_t label_len = sizeof(label);
+	size_t label_len = sizeof(label) - 1;
 	u8 last_update[32], profile_indication[SC_PKCS15_MAX_LABEL_SIZE];
 	size_t lupdate_len = sizeof(last_update) - 1, pi_len = sizeof(profile_indication) - 1;
 	size_t flags_len   = sizeof(ti->flags);
@@ -153,6 +153,10 @@ int sc_pkcs15_parse_tokeninfo(sc_context_t *ctx,
 	struct sc_asn1_entry asn1_toki_attrs[C_ASN1_TOKI_ATTRS_SIZE], asn1_tokeninfo[3], asn1_twlabel[3];
 
 	memset(last_update, 0, sizeof(last_update));
+	memset(label, 0, sizeof(label));
+	memset(profile_indication, 0, sizeof(profile_indication));
+	memset(mnfid, 0, sizeof(mnfid));
+
 	sc_copy_asn1_entry(c_asn1_twlabel, asn1_twlabel);
 	sc_copy_asn1_entry(c_asn1_toki_attrs, asn1_toki_attrs);
 	sc_copy_asn1_entry(c_asn1_tokeninfo, asn1_tokeninfo);