diff --git a/esphome/components/improv_serial/improv_serial_component.cpp b/esphome/components/improv_serial/improv_serial_component.cpp
index ab91ca6765..33514c9e06 100644
--- a/esphome/components/improv_serial/improv_serial_component.cpp
+++ b/esphome/components/improv_serial/improv_serial_component.cpp
@@ -267,16 +267,26 @@ bool ImprovSerialComponent::parse_improv_payload_(improv::ImprovCommand &command
       for (auto &scan : results) {
         if (scan.get_is_hidden())
           continue;
-        StringRef ssid = scan.get_ssid();
-        if (std::find(networks.begin(), networks.end(), ssid) != networks.end())
+        const char *ssid_cstr = scan.get_ssid().c_str();
+        // Check if we've already sent this SSID
+        bool duplicate = false;
+        for (const auto &seen : networks) {
+          if (strcmp(seen.c_str(), ssid_cstr) == 0) {
+            duplicate = true;
+            break;
+          }
+        }
+        if (duplicate)
           continue;
+        // Only allocate std::string after confirming it's not a duplicate
+        std::string ssid(ssid_cstr);
         // Send each ssid separately to avoid overflowing the buffer
         char rssi_buf[5];  // int8_t: -128 to 127, max 4 chars + null
         *int8_to_str(rssi_buf, scan.get_rssi()) = '\0';
         std::vector<uint8_t> data =
             improv::build_rpc_response(improv::GET_WIFI_NETWORKS, {ssid, rssi_buf, YESNO(scan.get_with_auth())}, false);
         this->send_response_(data);
-        networks.emplace_back(ssid.c_str(), ssid.size());
+        networks.push_back(std::move(ssid));
       }
       // Send empty response to signify the end of the list.
       std::vector<uint8_t> data =