diff --git a/misc/tools.func b/misc/tools.func
index 157610d2f..c702edaa2 100644
--- a/misc/tools.func
+++ b/misc/tools.func
@@ -2787,8 +2787,9 @@ function setup_java() {
   fi
 
   # Validate INSTALLED_VERSION is not empty if matched
-  local JDK_COUNT=$(dpkg -l 2>/dev/null | grep -c "temurin-.*-jdk" || echo "0")
-  if [[ -z "$INSTALLED_VERSION" && "$JDK_COUNT" -gt 0 ]]; then
+  local JDK_COUNT=0
+  JDK_COUNT=$(dpkg -l 2>/dev/null | grep -c "temurin-.*-jdk" || echo "0")
+  if [[ -z "$INSTALLED_VERSION" && "${JDK_COUNT:-0}" -gt 0 ]]; then
     msg_warn "Found Temurin JDK but cannot determine version"
     INSTALLED_VERSION="0"
   fi