diff --git a/cores/esp8266/spiffs_api.h b/cores/esp8266/spiffs_api.h
index 612b014b8a..4ce8d3e6ba 100644
--- a/cores/esp8266/spiffs_api.h
+++ b/cores/esp8266/spiffs_api.h
@@ -329,7 +329,7 @@ class SPIFFSFileImpl : public FileImpl
         if (mode == SeekEnd) {
             offset = -offset;
         }
-        auto rc = SPIFFS_lseek(_fs->getFs(), _fd, pos, (int) mode);
+        auto rc = SPIFFS_lseek(_fs->getFs(), _fd, offset, (int) mode);
         if (rc < 0) {
             DEBUGV("SPIFFS_lseek rc=%d\r\n", rc);
             return false;