diff --git a/config/prometheus.go b/config/prometheus.go
index c1de347c5..b3ed7ea15 100644
--- a/config/prometheus.go
+++ b/config/prometheus.go
@@ -133,6 +133,16 @@ func (c PrometheusAgentCfg) validate(cfg *CGRConfig) error {
 	if !c.Enabled {
 		return nil
 	}
+	for _, connID := range cfg.prometheusAgentCfg.CacheSConns {
+		if _, has := cfg.rpcConns[connID]; !has && !strings.HasPrefix(connID, utils.MetaInternal) {
+			return fmt.Errorf("<%s> connection with id: <%s> not defined", utils.PrometheusAgent, connID)
+		}
+	}
+	for _, connID := range cfg.prometheusAgentCfg.CoreSConns {
+		if _, has := cfg.rpcConns[connID]; !has && !strings.HasPrefix(connID, utils.MetaInternal) {
+			return fmt.Errorf("<%s> connection with id: <%s> not defined", utils.PrometheusAgent, connID)
+		}
+	}
 	for _, connID := range c.StatSConns {
 		if strings.HasPrefix(connID, utils.MetaInternal) && !cfg.statsCfg.Enabled {
 			return fmt.Errorf("<%s> not enabled but requested by <%s> component", utils.StatService, utils.PrometheusAgent)