diff --git a/bin/ki.bat b/bin/ki.bat
index c48c9f3..c3b5d47 100644
--- a/bin/ki.bat
+++ b/bin/ki.bat
@@ -1,6 +1,31 @@
 @echo off
+setlocal enabledelayedexpansion
 
-set SCRIPT_PATH=%~dp0
-set KI_SHELL=%SCRIPT_PATH%\..\lib\ki-shell.jar
+set SCRIPT_DIR=%~dp0
+set KI_SHELL=%SCRIPT_DIR%\..\lib\ki-shell.jar
+set JAVA_OPTS=%*
 
-java -jar %KI_SHELL% %*
+for /f "tokens=3" %%g in ('java -version 2^>^&1 ^| findstr /i "version"') do (
+    set JAVA_VERSION=%%g
+)
+
+set JAVA_VERSION=%JAVA_VERSION:"=%
+
+for /f "delims=. tokens=1-3" %%v in ("%JAVA_VERSION%") do (
+    if %%v EQU 1 (
+        if %%w LSS 8 (
+	        @echo java has version !JAVA_VERSION! but at least 1.8 is required
+	        exit /b 1
+	    )
+    ) else (
+	    set ADD_OPENS=--add-opens java.base/java.util=ALL-UNNAMED
+        if not defined JAVA_OPTS (
+	        set JAVA_OPTS=!ADD_OPENS!
+	    ) else (
+            set JAVA_OPTS=!JAVA_OPTS! !ADD_OPENS!
+        )
+    )
+    java !JAVA_OPTS! -jar !KI_SHELL!
+)
+
+endlocal
\ No newline at end of file
diff --git a/bin/ki.sh b/bin/ki.sh
index ba7d4ad..9d2821a 100755
--- a/bin/ki.sh
+++ b/bin/ki.sh
@@ -1,6 +1,41 @@
 #!/usr/bin/env bash
 
-SCRIPT_DIR="$( dirname $(realpath "$0") )"
+if command -v java &>/dev/null; then
+  _JAVA=java
+elif [[ -n "$JAVA_HOME" ]] && [[ -x "$JAVA_HOME/bin/java" ]]; then
+  _JAVA="$JAVA_HOME/bin/java"
+else
+  echo "java not found"
+  exit 1
+fi
+
+if [[ "$_JAVA" ]]; then
+  JAVA_VERSION=$("$_JAVA" -version 2>&1 | awk -F '"' '/version/ {print $2}')
+  if [[ "$JAVA_VERSION" =~ ^1\.[0-8]+ ]]; then
+    if [[ "$JAVA_VERSION" =~ ^1\.[0-7]+ ]]; then
+      echo "java has version $JAVA_VERSION but at least 1.8 is required"
+      exit 1
+    fi
+  else
+    ADD_OPENS="--add-opens java.base/java.util=ALL-UNNAMED"
+    if [[ "$JAVA_OPTS" ]]; then
+      JAVA_OPTS="$JAVA_OPTS $ADD_OPENS"
+    else
+      JAVA_OPTS=$ADD_OPENS
+    fi
+  fi
+fi
+
+command -v realpath &>/dev/null || realpath() {
+  SCRIPT_PATH=$([[ $1 == /* ]] && echo "$1" || echo "$PWD/${1#./}")
+  if [[ -L "$SCRIPT_PATH" ]]; then
+    readlink "$SCRIPT_PATH"
+  else
+    echo $SCRIPT_PATH
+  fi
+}
+
+SCRIPT_DIR="$(dirname "$(realpath "$0")")"
 KI_SHELL=$SCRIPT_DIR/../lib/ki-shell.jar
 
-java -jar ${KI_SHELL} $@
+$_JAVA $JAVA_OPTS -jar "${KI_SHELL}" $@