diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..da24ccb
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+/asdf/
diff --git a/.travis.yml b/.travis.yml
index 09564a5..0a6d930 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,5 @@
 language: c
-script: asdf plugin test golang . --asdf-plugin-gitref $TRAVIS_COMMIT go version
+script: asdf plugin test golang $TRAVIS_BUILD_DIR --asdf-plugin-gitref $TRAVIS_COMMIT go version
 before_script:
   - if [ $TRAVIS_OS_NAME = linux ]; then sudo apt-get install -y bsdmainutils; fi
   - git clone https://github.com/asdf-vm/asdf.git
@@ -11,6 +11,6 @@ matrix:
    - os: linux
      arch: ppc64le
    - os: linux
-     arch: arm64     
+     arch: arm64
    - os: osx
-     arch: amd64
\ No newline at end of file
+     arch: amd64
diff --git a/bin/list-legacy-filenames b/bin/list-legacy-filenames
index a57800e..553f6ce 100755
--- a/bin/list-legacy-filenames
+++ b/bin/list-legacy-filenames
@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-echo ".go-version"
+echo ".go-version go.mod"
diff --git a/bin/parse-legacy-file b/bin/parse-legacy-file
new file mode 100755
index 0000000..ef60682
--- /dev/null
+++ b/bin/parse-legacy-file
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+get_legacy_version() {
+  current_file="$1"
+  basename=$(basename -- "$current_file")
+
+  if [ "$basename" == "go.mod" ]; then
+    GOLANG_VERSION=$(grep 'go\s*[0-9]' "$current_file" |
+                       sed -e 's/.*heroku goVersion //' \
+                           -e 's/[[:space:]]//' \
+                           -e 's/go\(.*\)/\1/' |
+                       head -1
+      )
+  else
+    GOLANG_VERSION=$(cat "$current_file")
+  fi
+
+  echo "$GOLANG_VERSION"
+}
+
+get_legacy_version "$1"