diff --git a/esphome/components/api/proto.h b/esphome/components/api/proto.h
index 1552be5137..552b4a4625 100644
--- a/esphome/components/api/proto.h
+++ b/esphome/components/api/proto.h
@@ -408,7 +408,11 @@ class DumpBuffer {
   size_t pos() const { return pos_; }
   /// Update position after buf_append_printf call
   void set_pos(size_t pos) {
-    pos_ = pos;
+    if (pos >= CAPACITY) {
+      pos_ = CAPACITY - 1;
+    } else {
+      pos_ = pos;
+    }
     buf_[pos_] = '\0';
   }