diff --git a/esphome/components/prometheus/prometheus_handler.cpp b/esphome/components/prometheus/prometheus_handler.cpp
index 4f23f18942..aeadd60140 100644
--- a/esphome/components/prometheus/prometheus_handler.cpp
+++ b/esphome/components/prometheus/prometheus_handler.cpp
@@ -370,7 +370,8 @@ void PrometheusHandler::light_row_(AsyncResponseStream *stream, light::LightStat
     if (effect == "None") {
       stream->print(ESPHOME_F("None\"} 0\n"));
     } else {
-      stream->write(effect.c_str(), effect.size());
+      // c_str() is safe as effect names are null-terminated strings from codegen
+      stream->print(effect.c_str());
       stream->print(ESPHOME_F("\"} 1\n"));
     }
   }