diff --git a/.travis.yml b/.travis.yml
index 57dd101..dc66c28 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,54 @@ language: bash
 
 jobs:
   include:
+    - os: linux
+      dist: trusty
+      name: "Zabbix 4.0 @ Ubuntu 14 trusty, PHP default"
+      arch: amd64
+      addons:
+        apt:
+          sources:
+            - sourceline: 'deb http://repo.zabbix.com/zabbix/4.0/ubuntu trusty main'
+              key_url: "https://repo.zabbix.com/zabbix-official-repo.key"
+          packages:
+            - ca-certificates
+            - curl
+            - grep
+            - sed
+            - gawk
+            - lsof
+            - jq
+            - libfcgi0ldbl
+            - unzip
+            - zabbix-agent
+            - zabbix-get
+            - php5-fpm
+      before_script:
+        - sudo curl -o /usr/local/bin/shunit2 https://raw.githubusercontent.com/kward/shunit2/master/shunit2
+    - os: linux
+      dist: xenial
+      name: "Zabbix 4.0 @ Ubuntu 16 xenial, PHP default"
+      arch: amd64
+      addons:
+        apt:
+          sources:
+            - sourceline: 'deb http://repo.zabbix.com/zabbix/4.0/ubuntu xenial main'
+              key_url: "https://repo.zabbix.com/zabbix-official-repo.key"
+          packages:
+            - ca-certificates
+            - curl
+            - grep
+            - sed
+            - gawk
+            - lsof
+            - jq
+            - libfcgi0ldbl
+            - unzip
+            - zabbix-agent
+            - zabbix-get
+            - php-fpm
+      before_script:
+        - sudo curl -o /usr/local/bin/shunit2 https://raw.githubusercontent.com/kward/shunit2/master/shunit2
     - os: linux
       dist: bionic
       name: "Zabbix 4.0 @ Ubuntu 18 bionic, PHP default"
diff --git a/README.md b/README.md
index 1cee9bb..8e99473 100644
--- a/README.md
+++ b/README.md
@@ -123,14 +123,25 @@ Please refer to [Wiki](https://github.com/rvalitov/zabbix-php-fpm/wiki/Installat
 Please refer to [Wiki](https://github.com/rvalitov/zabbix-php-fpm/wiki/Testing-and-Troubleshooting).
 
 # Compatibility
-Should work with any version of PHP-FPM (starting with PHP 5.3.3), Zabbix 4.0.x and later.
-Can work with any version of ISPConfig as long as you have a valid PHP-FPM status page configuration there.
 
-Tested with:
-- [Travis CI](https://travis-ci.com/rvalitov/zabbix-php-fpm)
-- PHP 7.4, 7.3, 7.2, 7.1, 7.0
-- Zabbix 5.0.1, 4.4.4, 4.2.5, 4.0.20, 4.0.16, 4.0.4 
-- Debian 10, 9
-- Ubuntu 18
-- CentOS 7
-- ISPConfig v.3.1.14p2
\ No newline at end of file
+### System requirements
+
+- **PHP**. Should work with any version of PHP-FPM (starting with PHP 5.3.3)
+- **Zabbix** 4.0.x and later.
+- **ISPConfig**. Can work with any version of ISPConfig as long as you have a valid PHP-FPM status page configuration there.
+- Minimal `bash` version 4.
+- **OS**
+    - **Debian** 8 Jessie or newer
+    - **Ubuntu** 20 Focal, 18 Bionic, 16 Xenial, 14 Trusty. Other versions are supported if they are present in the [Zabbix repository](http://repo.zabbix.com/zabbix/4.0/ubuntu/dists/).
+    - **CentOS** 6 or newer
+    - **RHEL** 5 or newer
+
+### Tested with:
+
+- [**Travis CI**](https://travis-ci.com/rvalitov/zabbix-php-fpm)
+- **PHP** 7.4, 7.3, 7.2, 7.1, 7.0
+- **Zabbix** 5.0.1, 4.4.4, 4.2.5, 4.0.20, 4.0.16, 4.0.4 
+- **Debian** 10, 9
+- **Ubuntu** 18 Bionic, 16 Xenial, 14 Trusty
+- **CentOS** 7
+- **ISPConfig** v.3.1.14p2
diff --git a/tests/all.sh b/tests/all.sh
index 071f4ad..7b99cf0 100644
--- a/tests/all.sh
+++ b/tests/all.sh
@@ -7,13 +7,53 @@ MAX_POOLS=3
 MAX_PORTS=3
 MIN_PORT=9000
 
+function getPHPVersion() {
+  TEST_STRING=$1
+  PHP_VERSION=$(echo "$TEST_STRING" | grep -oP "(\d\.\d)")
+  if [[ -z "$PHP_VERSION" ]]; then
+    PHP_VERSION=$(echo "$TEST_STRING" | grep -oP "php(\d)" | grep -oP "(\d)")
+  fi
+  echo "$PHP_VERSION"
+}
+
+function getEtcPHPDirectory() {
+  LIST_OF_DIRS=(
+    "/etc/php/"
+    "/etc/php5/"
+  )
+  for PHP_TEST_DIR in "${LIST_OF_DIRS[@]}"; do
+    if [[ -d "$PHP_TEST_DIR" ]]; then
+      echo "$PHP_TEST_DIR"
+      return 0
+    fi
+  done
+
+  return 1
+}
+
+function getRunPHPDirectory() {
+  LIST_OF_DIRS=(
+    "/run/"
+    "/var/run/"
+  )
+  for PHP_TEST_DIR in "${LIST_OF_DIRS[@]}"; do
+    RESULT_DIR=$(find "$PHP_TEST_DIR" -name 'php*-fpm.sock' -type s -exec dirname {} \; 2>/dev/null | sort | head -n1)
+    if [[ -d "$RESULT_DIR" ]]; then
+      echo "$RESULT_DIR"
+      return 0
+    fi
+  done
+
+  return 1
+}
+
 copyPool() {
   ORIGINAL_FILE=$1
   POOL_NAME=$2
   POOL_SOCKET=$3
   POOL_TYPE=$4
   POOL_DIR=$(dirname "${ORIGINAL_FILE}")
-  PHP_VERSION=$(echo "$POOL_DIR" | grep -oP "(\d\.\d)")
+  PHP_VERSION=$(getPHPVersion "$POOL_DIR")
 
   NEW_POOL_FILE="$POOL_DIR/${POOL_NAME}.conf"
   sudo cp "$ORIGINAL_FILE" "$NEW_POOL_FILE"
@@ -31,7 +71,11 @@ copyPool() {
 setupPool() {
   POOL_FILE=$1
   POOL_DIR=$(dirname "${POOL_FILE}")
-  PHP_VERSION=$(echo "$POOL_DIR" | grep -oP "(\d\.\d)")
+  PHP_VERSION=$(getPHPVersion "$POOL_DIR")
+
+  PHP_RUN_DIR=$(getRunPHPDirectory)
+  EXIT_CODE=$?
+  assertEquals "Failed to find PHP run directory" "0" "$EXIT_CODE"
 
   #Delete all active pools except www.conf:
   find "$POOL_DIR" -name '*.conf' -type f -not -name 'www.conf' -exec rm -rf {} \;
@@ -44,7 +88,7 @@ setupPool() {
   #Create new socket pools
   for ((c = 1; c <= MAX_POOLS; c++)); do
     POOL_NAME="socket$c"
-    POOL_SOCKET="/run/php/php${PHP_VERSION}-fpm-${POOL_NAME}.sock"
+    POOL_SOCKET="${PHP_RUN_DIR}php${PHP_VERSION}-fpm-${POOL_NAME}.sock"
     copyPool "$POOL_FILE" "$POOL_NAME" "$POOL_SOCKET" "static"
   done
 
@@ -67,7 +111,11 @@ setupPool() {
 }
 
 setupPools() {
-  PHP_LIST=$(find /etc/php/ -name 'www.conf' -type f)
+  PHP_DIR=$(getEtcPHPDirectory)
+  EXIT_CODE=$?
+  assertEquals "Failed to find PHP directory" "0" "$EXIT_CODE"
+
+  PHP_LIST=$(find "$PHP_DIR" -name 'www.conf' -type f)
   while IFS= read -r pool; do
     if [[ -n $pool ]]; then
       setupPool "$pool"
@@ -76,17 +124,29 @@ setupPools() {
 }
 
 getNumberOfPHPVersions() {
-  PHP_COUNT=$(find /etc/php/ -name 'www.conf' -type f | wc -l)
+  PHP_DIR=$(getEtcPHPDirectory)
+  EXIT_CODE=$?
+  assertEquals "Failed to find PHP directory" "0" "$EXIT_CODE"
+
+  PHP_COUNT=$(find "$PHP_DIR" -name 'www.conf' -type f | wc -l)
   echo "$PHP_COUNT"
 }
 
 getAnySocket() {
+  PHP_DIR=$(getEtcPHPDirectory)
+  EXIT_CODE=$?
+  assertEquals "Failed to find PHP directory" "0" "$EXIT_CODE"
+
+  PHP_RUN_DIR=$(getRunPHPDirectory)
+  EXIT_CODE=$?
+  assertEquals "Failed to find PHP run directory" "0" "$EXIT_CODE"
+
   #Get any socket of PHP-FPM:
-  PHP_FIRST=$(find /etc/php/ -name 'www.conf' -type f | head -n1)
+  PHP_FIRST=$(find "$PHP_DIR" -name 'www.conf' -type f | sort | head -n1)
   assertNotNull "Failed to get PHP conf" "$PHP_FIRST"
-  PHP_VERSION=$(echo "$PHP_FIRST" | grep -oP "(\d\.\d)")
-  assertNotNull "Failed to get PHP version" "$PHP_VERSION"
-  PHP_POOL=$(find /run/php/ -name "php${PHP_VERSION}*.sock" -type s | head -n1)
+  PHP_VERSION=$(getPHPVersion "$PHP_FIRST")
+  assertNotNull "Failed to get PHP version for $PHP_FIRST" "$PHP_VERSION"
+  PHP_POOL=$(find "$PHP_RUN_DIR" -name "php${PHP_VERSION}*.sock" -type s 2>/dev/null | sort | head -n1)
   assertNotNull "Failed to get PHP${PHP_VERSION} socket" "$PHP_POOL"
   echo "$PHP_POOL"
 }
@@ -107,7 +167,7 @@ oneTimeSetUp() {
   #Install files:
   sudo cp "$TRAVIS_BUILD_DIR/zabbix/zabbix_php_fpm_discovery.sh" "/etc/zabbix"
   sudo cp "$TRAVIS_BUILD_DIR/zabbix/zabbix_php_fpm_status.sh" "/etc/zabbix"
-  sudo cp "$TRAVIS_BUILD_DIR/zabbix/userparameter_php_fpm.conf" "$(find /etc/zabbix/ -name 'zabbix_agentd*.d' -type d | head -n1)"
+  sudo cp "$TRAVIS_BUILD_DIR/zabbix/userparameter_php_fpm.conf" "$(find /etc/zabbix/ -name 'zabbix_agentd*.d' -type d | sort | head -n1)"
   sudo chmod +x /etc/zabbix/zabbix_php_fpm_discovery.sh
   sudo chmod +x /etc/zabbix/zabbix_php_fpm_status.sh
 
diff --git a/zabbix/zabbix_php_fpm_discovery.sh b/zabbix/zabbix_php_fpm_discovery.sh
index b322a61..d975fb8 100644
--- a/zabbix/zabbix_php_fpm_discovery.sh
+++ b/zabbix/zabbix_php_fpm_discovery.sh
@@ -71,6 +71,11 @@ if [[ ! -f ${S_WHOAMI} ]]; then
   exit 1
 fi
 
+if [[ "${BASH_VERSINFO:-0}" -lt 4 ]]; then
+  ${S_ECHO} "This script requires bash version 4.x or newer. Older version detected."
+  exit 1
+fi
+
 STATUS_PATH="/php-fpm-status"
 DEBUG_MODE=""
 ACTIVE_USER=$(${S_WHOAMI})