diff --git a/kubernetes/apps/otbr/deployment.yaml b/kubernetes/apps/otbr/deployment.yaml
index 698695f9..f8cd9dd1 100644
--- a/kubernetes/apps/otbr/deployment.yaml
+++ b/kubernetes/apps/otbr/deployment.yaml
@@ -145,9 +145,16 @@ spec:
                 # exists to prevent. Note the trailing `|| true`: this script
                 # runs under `set -e`, so a bare failing test would kill the
                 # container rather than log a warning.
+                #
+                # `tr -d '\r'` is load-bearing. ot-ctl speaks a serial-console
+                # protocol and terminates lines with CRLF, so `ot-ctl state`
+                # yields `leader\r` (7 bytes). That matches no shell glob, and
+                # the stray CR is invisible in logs — the first cut of this
+                # block printed "WARNING Thread not attached (state=leader)"
+                # while Thread was, in fact, the leader.
                 STATE=""
                 for i in $(seq 1 30); do
-                  STATE=$(ot-ctl state 2>/dev/null | head -1 || true)
+                  STATE=$(ot-ctl state 2>/dev/null | head -1 | tr -d '\r' || true)
                   case "$STATE" in
                     leader|router|child)
                       echo "otbr: Thread attached as ${STATE}"