diff --git a/esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp b/esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp
index 8cbf3e2e29..d96824f83d 100644
--- a/esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp
+++ b/esphome/components/seeed_mr60bha2/seeed_mr60bha2.cpp
@@ -30,8 +30,10 @@ void MR60BHA2Component::dump_config() {
 
 // main loop
 void MR60BHA2Component::loop() {
+  // All current UART available() implementations return >= 0,
+  // use <= 0 to future-proof against any that may return negative on error.
   int avail = this->available();
-  if (avail == 0) {
+  if (avail <= 0) {
     return;
   }
 
diff --git a/esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp b/esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp
index 259e60119d..de799fcfa8 100644
--- a/esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp
+++ b/esphome/components/seeed_mr60fda2/seeed_mr60fda2.cpp
@@ -49,8 +49,10 @@ void MR60FDA2Component::setup() {
 
 // main loop
 void MR60FDA2Component::loop() {
+  // All current UART available() implementations return >= 0,
+  // use <= 0 to future-proof against any that may return negative on error.
   int avail = this->available();
-  if (avail == 0) {
+  if (avail <= 0) {
     return;
   }