diff --git a/README.md b/README.md
index 52f79974..f395e49a 100644
--- a/README.md
+++ b/README.md
@@ -319,6 +319,7 @@ You don't have to do anything manually!
 1. Zilore (https://zilore.com)
 1. Loopia.se API
 1. acme-dns (https://github.com/joohoi/acme-dns)
+1. TELE3 (https://www.tele3.cz)
 
 And: 
 
diff --git a/acme.sh b/acme.sh
index 5e794a5a..713170b7 100755
--- a/acme.sh
+++ b/acme.sh
@@ -4676,19 +4676,19 @@ _installcert() {
     if [ -f "$_real_cert" ] && [ ! "$IS_RENEW" ]; then
       cp "$_real_cert" "$_backup_path/cert.bak"
     fi
-    cat "$CERT_PATH" >"$_real_cert"
+    cat "$CERT_PATH" >"$_real_cert" || return 1
   fi
 
   if [ "$_real_ca" ]; then
     _info "Installing CA to:$_real_ca"
     if [ "$_real_ca" = "$_real_cert" ]; then
       echo "" >>"$_real_ca"
-      cat "$CA_CERT_PATH" >>"$_real_ca"
+      cat "$CA_CERT_PATH" >>"$_real_ca" || return 1
     else
       if [ -f "$_real_ca" ] && [ ! "$IS_RENEW" ]; then
         cp "$_real_ca" "$_backup_path/ca.bak"
       fi
-      cat "$CA_CERT_PATH" >"$_real_ca"
+      cat "$CA_CERT_PATH" >"$_real_ca" || return 1
     fi
   fi
 
@@ -4698,9 +4698,9 @@ _installcert() {
       cp "$_real_key" "$_backup_path/key.bak"
     fi
     if [ -f "$_real_key" ]; then
-      cat "$CERT_KEY_PATH" >"$_real_key"
+      cat "$CERT_KEY_PATH" >"$_real_key" || return 1
     else
-      cat "$CERT_KEY_PATH" >"$_real_key"
+      cat "$CERT_KEY_PATH" >"$_real_key" || return 1
       chmod 600 "$_real_key"
     fi
   fi
@@ -4710,7 +4710,7 @@ _installcert() {
     if [ -f "$_real_fullchain" ] && [ ! "$IS_RENEW" ]; then
       cp "$_real_fullchain" "$_backup_path/fullchain.bak"
     fi
-    cat "$CERT_FULLCHAIN_PATH" >"$_real_fullchain"
+    cat "$CERT_FULLCHAIN_PATH" >"$_real_fullchain" || return 1
   fi
 
   if [ "$_reload_cmd" ]; then
diff --git a/dnsapi/README.md b/dnsapi/README.md
index aa8ae6be..ef6c9d09 100644
--- a/dnsapi/README.md
+++ b/dnsapi/README.md
@@ -863,7 +863,19 @@ acme.sh --issue --dns dns_acmedns -d example.com -d www.example.com
 
 The credentials will be saved in `~/.acme.sh/account.conf` and will
 be reused when needed.
+## 46. Use TELE3 API
 
+First you need to login to your TELE3 account to set your API-KEY.
+https://www.tele3.cz/system-acme-api.html
+
+```
+export TELE3_Key="MS2I4uPPaI..."
+export TELE3_Secret="kjhOIHGJKHg"
+
+acme.sh --issue --dns dns_tele3 -d example.com -d *.example.com
+```
+
+The TELE3_Key and TELE3_Secret will be saved in ~/.acme.sh/account.conf and will be reused when needed.
 # Use custom API
 
 If your API is not supported yet, you can write your own DNS API.
diff --git a/dnsapi/dns_tele3.sh b/dnsapi/dns_tele3.sh
new file mode 100644
index 00000000..76c90913
--- /dev/null
+++ b/dnsapi/dns_tele3.sh
@@ -0,0 +1,69 @@
+#!/usr/bin/env sh
+#
+# tele3.cz DNS API
+#
+# Author: Roman Blizik
+# Report Bugs here: https://github.com/par-pa/acme.sh
+#
+# --
+# export TELE3_Key="MS2I4uPPaI..."
+# export TELE3_Secret="kjhOIHGJKHg"
+# --
+
+TELE3_API="https://www.tele3.cz/acme/"
+
+########  Public functions  #####################
+
+dns_tele3_add() {
+  _info "Using TELE3 DNS"
+  data="\"ope\":\"add\", \"domain\":\"$1\", \"value\":\"$2\""
+  if ! _tele3_call; then
+    _err "Publish zone failed"
+    return 1
+  fi
+
+  _info "Zone published"
+}
+
+dns_tele3_rm() {
+  _info "Using TELE3 DNS"
+  data="\"ope\":\"rm\", \"domain\":\"$1\", \"value\":\"$2\""
+  if ! _tele3_call; then
+    _err "delete TXT record failed"
+    return 1
+  fi
+
+  _info "TXT record successfully deleted"
+}
+
+####################  Private functions below  ##################################
+
+_tele3_init() {
+  TELE3_Key="${TELE3_Key:-$(_readaccountconf_mutable TELE3_Key)}"
+  TELE3_Secret="${TELE3_Secret:-$(_readaccountconf_mutable TELE3_Secret)}"
+  if [ -z "$TELE3_Key" ] || [ -z "$TELE3_Secret" ]; then
+    TELE3_Key=""
+    TELE3_Secret=""
+    _err "You must export variables: TELE3_Key and TELE3_Secret"
+    return 1
+  fi
+
+  #save the config variables to the account conf file.
+  _saveaccountconf_mutable TELE3_Key "$TELE3_Key"
+  _saveaccountconf_mutable TELE3_Secret "$TELE3_Secret"
+}
+
+_tele3_call() {
+  _tele3_init
+  data="{\"key\":\"$TELE3_Key\", \"secret\":\"$TELE3_Secret\", $data}"
+
+  _debug data "$data"
+
+  response="$(_post "$data" "$TELE3_API" "" "POST")"
+  _debug response "$response"
+
+  if [ "$response" != "success" ]; then
+    _err "$response"
+    return 1
+  fi
+}