diff --git a/backend/Dockerfile b/backend/Dockerfile
index 9122ded..983908a 100644
--- a/backend/Dockerfile
+++ b/backend/Dockerfile
@@ -2,8 +2,13 @@ FROM openjdk:17-jdk-slim
 
 WORKDIR /app
 
-# Install Maven and PostgreSQL client tools
-RUN apt-get update && apt-get install -y maven postgresql-client && rm -rf /var/lib/apt/lists/*
+# Install Maven and PostgreSQL 15 client tools
+RUN apt-get update && apt-get install -y wget ca-certificates gnupg maven && \
+    wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add - && \
+    echo "deb http://apt.postgresql.org/pub/repos/apt/ bullseye-pgdg main" > /etc/apt/sources.list.d/pgdg.list && \
+    apt-get update && \
+    apt-get install -y postgresql-client-15 && \
+    rm -rf /var/lib/apt/lists/*
 
 # Copy source code
 COPY . .