diff --git a/platformio/__init__.py b/platformio/__init__.py
index ebcb7a28..2aac70cf 100644
--- a/platformio/__init__.py
+++ b/platformio/__init__.py
@@ -14,7 +14,7 @@
 
 import sys
 
-VERSION = (2, 7, "0.dev11")
+VERSION = (2, 7, "0.dev12")
 __version__ = ".".join([str(s) for s in VERSION])
 
 __title__ = "platformio"
diff --git a/platformio/builder/scripts/espressif.py b/platformio/builder/scripts/espressif.py
index ec233db1..2d5b2023 100644
--- a/platformio/builder/scripts/espressif.py
+++ b/platformio/builder/scripts/espressif.py
@@ -116,7 +116,7 @@ env.Replace(
     UPLOADEROTAFLAGS=[
         "--debug",
         "--progress",
-        "-i", "$UPLOAD_PORT",
+        "-i", '"$UPLOAD_PORT"',
         "$UPLOAD_FLAGS"
     ],