diff --git a/action.yml b/action.yml
index f4340ec..578503f 100644
--- a/action.yml
+++ b/action.yml
@@ -27,7 +27,7 @@ inputs:
   architecture:
     description: 'The architecture of Flutter SDK executable (x64 or arm64)'
     required: false
-    default: 'x64'
+    default: ${{ runner.arch }}
 runs:
   using: 'composite'
   steps:
diff --git a/setup.sh b/setup.sh
index 1cb0e59..8d048aa 100755
--- a/setup.sh
+++ b/setup.sh
@@ -25,7 +25,7 @@ wildcard_version() {
     jq --arg channel "$1" --arg version "$2" '.releases | map(select(.channel==$channel) | select(.version | startswith($version) )) | first'
     fi
   elif [[ $1 == any ]]; then
-    jq --arg version "$2" --arg arch "$ARCH" '.releases | map(select(.version | startswith($version)) | select(.dart_sdk_arch == null or .dart_sdk_arch == $arch)) | first'    
+    jq --arg version "$2" --arg arch "$ARCH" '.releases | map(select(.version | startswith($version)) | select(.dart_sdk_arch == null or .dart_sdk_arch == $arch)) | first'
   else
     jq --arg channel "$1" --arg version "$2" --arg arch "$ARCH" '.releases | map(select(.channel==$channel) | select(.version | startswith($version) ) | select(.dart_sdk_arch == null or .dart_sdk_arch == $arch)) | first'
   fi
@@ -95,7 +95,7 @@ done
 
 CHANNEL="${@:$OPTIND:1}"
 VERSION="${@:$OPTIND+1:1}"
-ARCH="${@:$OPTIND+2:1}"
+ARCH=$(echo "${@:$OPTIND+2:1}" | awk '{print tolower($0)}')
 
 SDK_CACHE="$(transform_path ${CACHE_PATH})"
 PUB_CACHE="$(transform_path ${CACHE_PATH}/.pub-cache)"