diff --git a/demo/.shellcheckrc b/demo/.shellcheckrc
new file mode 100644
index 0000000..b988374
--- /dev/null
+++ b/demo/.shellcheckrc
@@ -0,0 +1,5 @@
+# ShellCheck configuration for the TSYS Developer Support Stack
+# These rules are inherent to the environment-driven (dynamic source) design:
+#   SC1090 - can't follow non-constant source (e.g. `source "$ENV_FILE"`)
+#   SC1091 - not following external file specified as input (demo.env)
+disable=SC1090,SC1091
diff --git a/demo/scripts/demo-test.sh b/demo/scripts/demo-test.sh
index a9ee803..68f8e19 100755
--- a/demo/scripts/demo-test.sh
+++ b/demo/scripts/demo-test.sh
@@ -74,7 +74,7 @@ test_service_health() {
     log_test "Service health"
     local unhealthy=0
     while IFS= read -r line; do
-        local name status
+        local name
         name=$(echo "$line" | awk '{print $1}')
         [[ "$name" == "NAMES" || -z "$name" ]] && continue
         if echo "$line" | grep -q "(healthy)"; then
diff --git a/demo/scripts/validate-all.sh b/demo/scripts/validate-all.sh
index e74e400..1b88003 100755
--- a/demo/scripts/validate-all.sh
+++ b/demo/scripts/validate-all.sh
@@ -17,8 +17,8 @@ BLUE='\033[0;34m'
 NC='\033[0m'
 
 log_validation() { echo -e "${BLUE}[VALIDATE]${NC} $1"; }
-log_pass()       { echo -e "${GREEN}[PASS]${NC} $1"; ((VALIDATION_PASSED++)); }
-log_fail()       { echo -e "${RED}[FAIL]${NC} $1"; ((VALIDATION_FAILED++)); }
+log_pass()       { echo -e "${GREEN}[PASS]${NC} $1"; VALIDATION_PASSED=$((VALIDATION_PASSED + 1)); }
+log_fail()       { echo -e "${RED}[FAIL]${NC} $1"; VALIDATION_FAILED=$((VALIDATION_FAILED + 1)); }
 
 validate_yaml_files() {
     log_validation "Validating YAML files with yamllint..."