diff --git a/builder/main.py b/builder/main.py
index 6d8fa03..2d32193 100644
--- a/builder/main.py
+++ b/builder/main.py
@@ -34,12 +34,13 @@ env.Replace(
     AS="xtensa-esp32-elf-as",
     CC="xtensa-esp32-elf-gcc",
     CXX="xtensa-esp32-elf-g++",
+    GDB="xtensa-esp32-elf-gdb",
     OBJCOPY=join(
         platform.get_package_dir("tool-esptoolpy") or "", "esptool.py"),
     RANLIB="xtensa-esp32-elf-ranlib",
     SIZETOOL="xtensa-esp32-elf-size",
 
-    ARFLAGS=["rcs"],
+    ARFLAGS=["rc"],
 
     ASFLAGS=["-x", "assembler-with-cpp"],
 
diff --git a/platform.json b/platform.json
index a285a93..d59449f 100644
--- a/platform.json
+++ b/platform.json
@@ -12,7 +12,7 @@
     "type": "git",
     "url": "https://github.com/platformio/platform-espressif32.git"
   },
-  "version": "0.9.0",
+  "version": "0.9.1",
   "packageRepositories": [
     "https://dl.bintray.com/platformio/dl-packages/manifest.json",
     "http://dl.platformio.org/packages/manifest.json",