diff --git a/appveyor.yml b/appveyor.yml
index 0900befa..4e9ae14f 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -1,5 +1,5 @@
 environment:
-  - CTEST_OUTPUT_ON_FAILURE: 1
+  CTEST_OUTPUT_ON_FAILURE: 1
   matrix:
   - Build: msvc
     Config: Debug