diff --git a/command/agent/consul/service_client.go b/command/agent/consul/service_client.go
index 2934e24eeb0..3a22848f098 100644
--- a/command/agent/consul/service_client.go
+++ b/command/agent/consul/service_client.go
@@ -1704,7 +1704,7 @@ func maybeConnectSidecar(id string) bool {
 }
 
 var (
-	sidecarProxyCheckRe = regexp.MustCompile(`service:_nomad-.+-sidecar-proxy(:[\d]+)?`)
+	sidecarProxyCheckRe = regexp.MustCompile(`^service:_nomad-.+-sidecar-proxy(:[\d]+)?$`)
 )
 
 // maybeSidecarProxyCheck returns true if the ID likely matches a Nomad generated
diff --git a/command/agent/consul/service_client_test.go b/command/agent/consul/service_client_test.go
index 30ef7559291..9cacaa38ddc 100644
--- a/command/agent/consul/service_client_test.go
+++ b/command/agent/consul/service_client_test.go
@@ -636,5 +636,7 @@ func TestSyncLogic_maybeSidecarProxyCheck(t *testing.T) {
 	try("service:_nomad-task-2f5fb517-57d4-44ee-7780-dc1cb6e103cd-group-api-count-api-9001-sidecar-proxy:2", true)
 	try("service:_nomad-task-2f5fb517-57d4-44ee-7780-dc1cb6e103cd-group-api-count-api-9001", false)
 	try("_nomad-task-2f5fb517-57d4-44ee-7780-dc1cb6e103cd-group-api-count-api-9001-sidecar-proxy:1", false)
+	try("service:_nomad-task-2f5fb517-57d4-44ee-7780-dc1cb6e103cd-group-api-count-api-9001-sidecar-proxy:X", false)
+	try("service:_nomad-task-2f5fb517-57d4-44ee-7780-dc1cb6e103cd-group-api-count-api-9001-sidecar-proxy: ", false)
 	try("service", false)
 }