diff --git a/.appveyor.yml b/.appveyor.yml
index ab43676f..2feae079 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -8,7 +8,7 @@ build_script:
   - cmd: msbuild .\update\build\win32\update.vcxproj
   - cmd: msbuild .\standalone\build\win32\Tracy.vcxproj
   - cmd: msbuild .\capture\build\win32\capture.vcxproj
-  - sh: sudo apt-get -y install libglfw3-dev libgtk2.0-dev
+  - sh: sudo apt-get update && sudo apt-get -y install libglfw3-dev libgtk2.0-dev
   - sh: make -C update/build/unix debug release
   - sh: make -C standalone/build/unix debug release
   - sh: make -C capture/build/unix debug release