diff --git a/appveyor.yml b/appveyor.yml
index eed7fea9..dc06522e 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -4,6 +4,7 @@ configuration:
 
 install:
   - set PATH=C:\Program Files (x86)\MSBuild\12.0\bin\;%PATH%
+  - 7z
 
 before_build: cmake -DFMT_EXTRA_TESTS=ON .