diff --git a/diagnose.py b/diagnose.py
index d0879ec..e7ec513 100644
--- a/diagnose.py
+++ b/diagnose.py
@@ -68,7 +68,7 @@ class DiagnosticsRunner:
             f' echo "=== ip_route ===";'
             f' ip route show dev {q} 2>/dev/null;'
             f' echo "=== dmesg ===";'
-            f' dmesg 2>/dev/null | grep {q} | tail -50;'
+            f' dmesg 2>/dev/null | grep -F -- {q} | tail -50;'
             f' echo "=== lldpctl ===";'
             f' lldpctl 2>/dev/null || echo "lldpd not running";'
             f' echo "=== end ==="'