diff --git a/installation/install-openems.sh b/installation/install-openems.sh
index 3af83e2..36b29e8 100755
--- a/installation/install-openems.sh
+++ b/installation/install-openems.sh
@@ -66,9 +66,18 @@ fi
 
 echo -e "${GREEN}installing required packages...${NC}"
 sudo apt-get update
-sudo apt-get install -y openjdk-17-jdk
+
+# Add Adoptium repository for Temurin Java
+echo -e "${GREEN}Adding Adoptium repository for Temurin Java...${NC}"
+sudo apt-get install -y wget apt-transport-https
+wget -qO - https://packages.adoptium.net/artifactory/api/gpg/key/public | sudo apt-key add -
+echo "deb https://packages.adoptium.net/artifactory/deb $(lsb_release -cs) main" | sudo tee /etc/apt/sources.list.d/adoptium.list
+
+# Update and install Temurin Java 21
+sudo apt-get update
+sudo apt-get install -y temurin-21-jdk
+
 sudo apt-get install -y nginx
-sudo apt-get install -y wget
 
 echo -e "${GREEN}done${NC}"