diff --git a/Jenkinsfile b/Jenkinsfile
index 4d733ab..bb613ae 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -42,15 +42,28 @@ pipeline {
             apt-get update
             apt-get install -y --no-install-recommends \
               ca-certificates curl unzip jq git openjdk-21-jre-headless
+
+            # --- Install ICU runtime (Debian uses versioned package names) ---
+            if ! ldconfig -p | grep -qi libicu; then
+              PKG="$(apt-cache search '^libicu[0-9]+$' | awk '{print $1}' | head -n1 || true)"
+              if [ -n "$PKG" ]; then
+                echo "Installing ICU package: ${PKG}"
+                apt-get install -y --no-install-recommends "${PKG}"
+              else
+                # Fallback: dev package also provides the libs (heavier)
+                echo "Falling back to libicu-dev..."
+                apt-get install -y --no-install-recommends libicu-dev
+              fi
+            fi
           fi
 
-          mkdir -p "${DOTNET_ROOT}"
+          # Install .NET SDK locally for the build user
+          mkdir -p "${WORKSPACE}/.dotnet"
           curl -fsSL https://dot.net/v1/dotnet-install.sh -o dotnet-install.sh
-          bash dotnet-install.sh --channel 9.0 --install-dir "${DOTNET_ROOT}"
-          dotnet --info
+          bash dotnet-install.sh --channel 9.0 --install-dir "${WORKSPACE}/.dotnet"
 
-          # เตรียม cache สำหรับ Dependency-Check
-          mkdir -p "${DC_DATA}"
+          export PATH="${WORKSPACE}/.dotnet:${PATH}"
+          dotnet --info
         '''
       }
     }