diff --git a/lib/tests/util.c b/lib/tests/util.c
index efbce40..8b103c9 100644
--- a/lib/tests/util.c
+++ b/lib/tests/util.c
@@ -145,7 +145,7 @@ START_TEST(test_read_write_list_delete_cert) {
   size_t read_cert_len = 0;
 
   {
-    res = ykpiv_util_write_cert(g_state, YKPIV_KEY_AUTHENTICATION, (uint8_t*)g_cert, sizeof(g_cert));
+    res = ykpiv_util_write_cert(g_state, YKPIV_KEY_AUTHENTICATION, (uint8_t*)g_cert, sizeof(g_cert), YKPIV_CERTINFO_UNCOMPRESSED);
     ck_assert_int_eq(res, YKPIV_OK);
 
     res = ykpiv_util_read_cert(g_state, YKPIV_KEY_AUTHENTICATION, &read_cert, &read_cert_len);
@@ -411,7 +411,7 @@ START_TEST(test_generate_key) {
   ykpiv_rc res;
   uint8_t *mod, *exp;
   size_t mod_len, exp_len;
-  res = ykpiv_util_write_cert(g_state, YKPIV_KEY_AUTHENTICATION, (uint8_t*)g_cert, sizeof(g_cert));
+  res = ykpiv_util_write_cert(g_state, YKPIV_KEY_AUTHENTICATION, (uint8_t*)g_cert, sizeof(g_cert), YKPIV_CERTINFO_UNCOMPRESSED);
   ck_assert_int_eq(res, YKPIV_OK);
   res = ykpiv_util_generate_key(g_state,
                                 YKPIV_KEY_AUTHENTICATION,
@@ -666,7 +666,7 @@ uint8_t *alloc_auth_cert() {
   uint8_t *read_cert = NULL;
   size_t read_cert_len = 0;
 
-  res = ykpiv_util_write_cert(g_state, YKPIV_KEY_AUTHENTICATION, (uint8_t*)g_cert, sizeof(g_cert));
+  res = ykpiv_util_write_cert(g_state, YKPIV_KEY_AUTHENTICATION, (uint8_t*)g_cert, sizeof(g_cert), YKPIV_CERTINFO_UNCOMPRESSED);
   ck_assert_int_eq(res, YKPIV_OK);
 
   res = ykpiv_util_read_cert(g_state, YKPIV_KEY_AUTHENTICATION, &read_cert, &read_cert_len);
diff --git a/lib/util.c b/lib/util.c
index f69e146..aa2b1f3 100644
--- a/lib/util.c
+++ b/lib/util.c
@@ -58,7 +58,7 @@ const uint8_t CCC_TMPL[] = {
 };
 
 static ykpiv_rc _read_certificate(ykpiv_state *state, uint8_t slot, uint8_t *buf, size_t *buf_len);
-static ykpiv_rc _write_certificate(ykpiv_state *state, uint8_t slot, uint8_t *data, size_t data_len);
+static ykpiv_rc _write_certificate(ykpiv_state *state, uint8_t slot, uint8_t *data, size_t data_len, uint8_t certinfo);
 
 static ykpiv_rc _read_metadata(ykpiv_state *state, uint8_t tag, uint8_t* data, size_t* pcb_data);
 static ykpiv_rc _write_metadata(ykpiv_state *state, uint8_t tag, uint8_t *data, size_t cb_data);
@@ -293,13 +293,13 @@ Cleanup:
   return res;
 }
 
-ykpiv_rc ykpiv_util_write_cert(ykpiv_state *state, uint8_t slot, uint8_t *data, size_t data_len) {
+ykpiv_rc ykpiv_util_write_cert(ykpiv_state *state, uint8_t slot, uint8_t *data, size_t data_len, uint8_t certinfo) {
   ykpiv_rc res = YKPIV_OK;
 
   if (YKPIV_OK != (res = _ykpiv_begin_transaction(state))) return YKPIV_PCSC_ERROR;
   if (YKPIV_OK != (res = _ykpiv_ensure_application_selected(state))) goto Cleanup;
 
-  res = _write_certificate(state, slot, data, data_len);
+  res = _write_certificate(state, slot, data, data_len, certinfo);
 
 Cleanup:
 
@@ -308,7 +308,7 @@ Cleanup:
 }
 
 ykpiv_rc ykpiv_util_delete_cert(ykpiv_state *state, uint8_t slot) {
-  return ykpiv_util_write_cert(state, slot, NULL, 0);
+  return ykpiv_util_write_cert(state, slot, NULL, 0, 0);
 }
 
 ykpiv_rc ykpiv_util_block_puk(ykpiv_state *state) {
@@ -1252,7 +1252,7 @@ static ykpiv_rc _read_certificate(ykpiv_state *state, uint8_t slot, uint8_t *buf
   return res;
 }
 
-static ykpiv_rc _write_certificate(ykpiv_state *state, uint8_t slot, uint8_t *data, size_t data_len) {
+static ykpiv_rc _write_certificate(ykpiv_state *state, uint8_t slot, uint8_t *data, size_t data_len, uint8_t certinfo) {
   // TREV TODO: should this select application?
   uint8_t buf[CB_OBJ_MAX];
   size_t cbBuf = sizeof(buf);
@@ -1290,8 +1290,8 @@ static ykpiv_rc _write_certificate(ykpiv_state *state, uint8_t slot, uint8_t *da
   // write compression info and LRC trailer
   buf[offset++] = TAG_CERT_COMPRESS;
   buf[offset++] = 0x01;
-  buf[offset++] = 0x00; // TODO: Handle compression when certificate exceeds buffer size
-  buf[offset++] = TAG_CERT_LRC; // LRC
+  buf[offset++] = certinfo == YKPIV_CERTINFO_GZIP ? 0x01 : 0x00;
+  buf[offset++] = TAG_CERT_LRC;
   buf[offset++] = 00;
 
   // write onto device
diff --git a/lib/ykpiv.h b/lib/ykpiv.h
index e39d9a8..28d2a73 100644
--- a/lib/ykpiv.h
+++ b/lib/ykpiv.h
@@ -198,6 +198,8 @@ extern "C"
 
 #define YKPIV_OBJ_ATTESTATION 0x5fff01
 
+#define YKPIV_OBJ_MAX_SIZE 3072
+
 #define YKPIV_INS_VERIFY 0x20
 #define YKPIV_INS_CHANGE_REFERENCE 0x24
 #define YKPIV_INS_RESET_RETRY 0x2c
@@ -241,6 +243,8 @@ extern "C"
 #define YKPIV_RETRIES_DEFAULT 3
 #define YKPIV_RETRIES_MAX 0xff
 
+#define YKPIV_CERTINFO_UNCOMPRESSED 0
+#define YKPIV_CERTINFO_GZIP 1
 
 //
 // UTIL
@@ -291,7 +295,7 @@ extern "C"
 
   ykpiv_rc ykpiv_util_list_keys(ykpiv_state *state, uint8_t *key_count, ykpiv_key **data, size_t *data_len);
   ykpiv_rc ykpiv_util_read_cert(ykpiv_state *state, uint8_t slot, uint8_t **data, size_t *data_len);
-  ykpiv_rc ykpiv_util_write_cert(ykpiv_state *state, uint8_t slot, uint8_t *data, size_t data_len);
+  ykpiv_rc ykpiv_util_write_cert(ykpiv_state *state, uint8_t slot, uint8_t *data, size_t data_len, uint8_t certinfo);
   ykpiv_rc ykpiv_util_delete_cert(ykpiv_state *state, uint8_t slot);
 
   /**
diff --git a/tool/util.c b/tool/util.c
index baea3f1..3ae4119 100644
--- a/tool/util.c
+++ b/tool/util.c
@@ -255,6 +255,51 @@ int set_length(unsigned char *buffer, int length) {
   }
 }
 
+int get_slot_hex(enum enum_slot slot_enum) {
+  int slot = -1;
+
+  switch (slot_enum) {
+    case slot_arg_9a:
+      slot = 0x9a;
+      break;
+    case slot_arg_9c:
+    case slot_arg_9d:
+    case slot_arg_9e:
+      slot = 0x9c + ((int)slot_enum - (int)slot_arg_9c);
+      break;
+    case slot_arg_82:
+    case slot_arg_83:
+    case slot_arg_84:
+    case slot_arg_85:
+    case slot_arg_86:
+    case slot_arg_87:
+    case slot_arg_88:
+    case slot_arg_89:
+    case slot_arg_8a:
+    case slot_arg_8b:
+    case slot_arg_8c:
+    case slot_arg_8d:
+    case slot_arg_8e:
+    case slot_arg_8f:
+    case slot_arg_90:
+    case slot_arg_91:
+    case slot_arg_92:
+    case slot_arg_93:
+    case slot_arg_94:
+    case slot_arg_95:
+      slot = 0x82 + ((int)slot_enum - (int)slot_arg_82);
+      break;
+    case slot_arg_f9:
+      slot = 0xf9;
+      break;
+    case slot__NULL:
+    default:
+      slot = -1;
+  }
+
+  return slot;
+}
+
 int get_object_id(enum enum_slot slot) {
   int object;
 
diff --git a/tool/util.h b/tool/util.h
index 4f61713..a1f15b5 100644
--- a/tool/util.h
+++ b/tool/util.h
@@ -47,6 +47,7 @@ int get_length(const unsigned char*, int*);
 X509_NAME *parse_name(const char*);
 unsigned char get_algorithm(EVP_PKEY*);
 FILE *open_file(const char*, int);
+int get_slot_hex(enum enum_slot slot_enum);
 int get_object_id(enum enum_slot slot);
 int key_to_object_id(int key);
 bool set_component(unsigned char *in_ptr, const BIGNUM *bn, int element_len);
diff --git a/tool/yubico-piv-tool.c b/tool/yubico-piv-tool.c
index 58ed1bd..adde591 100644
--- a/tool/yubico-piv-tool.c
+++ b/tool/yubico-piv-tool.c
@@ -495,35 +495,18 @@ static bool import_cert(ykpiv_state *state, enum enum_key_format cert_format,
   }
 
   {
-    unsigned char certdata[3072];
+    unsigned char certdata[YKPIV_OBJ_MAX_SIZE];
     unsigned char *certptr = certdata;
-    int object = get_object_id(slot);
     ykpiv_rc res;
-
-    if(4 + cert_len + 5 > sizeof(certdata)) { /* 4 is prefix size, 5 is postfix size */
-      fprintf(stderr, "Certificate is too large to fit in buffer.\n");
-      goto import_cert_out;
-    }
-
-    *certptr++ = 0x70;
-    certptr += set_length(certptr, cert_len);
     if (compress) {
-      if (fread(certptr, 1, (size_t)cert_len, input_file) != (size_t)cert_len) {
+      if (fread(certdata, 1, (size_t)cert_len, input_file) != (size_t)cert_len) {
         fprintf(stderr, "Failed to read compressed certificate\n");
         goto import_cert_out;
       }
-      certptr += cert_len;
     } else {
-      /* i2d_X509 increments certptr here.. */
       i2d_X509(cert, &certptr);
     }
-    *certptr++ = 0x71;
-    *certptr++ = 1;
-    *certptr++ = compress; /* certinfo (gzip etc) */
-    *certptr++ = 0xfe; /* LRC */
-    *certptr++ = 0;
-
-    if((res = ykpiv_save_object(state, object, certdata, (size_t)(certptr - certdata))) != YKPIV_OK) {
+    if ((res = ykpiv_util_write_cert(state, get_slot_hex(slot), certdata, cert_len, compress)) != YKPIV_OK) {
       fprintf(stderr, "Failed commands with device: %s\n", ykpiv_strerror(res));
     } else {
       ret = true;