diff --git a/.github/appveyor.yml b/.github/appveyor.yml
index 55f03c38d267ca..a4c11df2795ed1 100644
--- a/.github/appveyor.yml
+++ b/.github/appveyor.yml
@@ -10,12 +10,13 @@ cache:
 before_build:
   - ps: |+
       if ($env:APPVEYOR_RE_BUILD) {
-        # If we were explicitly told to rebuild, do a full build
+        echo 'Doing full build due to re-build request.'
       } elseif (!$env:APPVEYOR_PULL_REQUEST_HEAD_COMMIT) {
-        # It's not a pull request, do a full build
+        echo 'Not a PR, doing full build.'
       } else {
         $mergebase = git merge-base $env:APPVEYOR_PULL_REQUEST_HEAD_COMMIT $env:APPVEYOR_REPO_BRANCH
-        If (git diff --name-only $mergebase | grep -qvE '(\.rst$)|(^Doc)|(^Misc)') {
+        $changes = git diff --name-only HEAD $mergebase | grep -vE '(\.rst$)|(^Doc)|(^Misc)'
+        If (!$changes) {
           echo 'Only docs were updated, stopping build process.'
           Exit-AppveyorBuild
         }