diff --git a/linux/esptun.c b/linux/esptun.c
index c02afa7..1356d49 100644
--- a/linux/esptun.c
+++ b/linux/esptun.c
@@ -371,16 +371,17 @@ static bool esp_read_responses(int fd, bool early_terminate)
 
                 /* On non-final response, keep reading. */
             } else {
-                if (esp_end == ESP_BUFSIZE) {
-                    /* Buffer full but command wasn't complete - this isn't good,
-                     * exit to prevent looping forever. */
-                    my_err("Buffer full with unterminated command");
-                }
                 break;
             }
             ptr += len;
         }
 
+        if (ptr == 0 && esp_end == ESP_BUFSIZE) {
+            /* Buffer full there was no progress processing responses - this isn't good,
+             * exit to prevent looping forever. */
+            my_err("Buffer full with unterminated command");
+        }
+
         /* Remove processed responses from esp_buffer by shifting bytes. */
         memmove(esp_buffer, &esp_buffer[ptr], esp_end - ptr);
         esp_end -= ptr;