diff --git a/.appveyor.yml b/.appveyor.yml
index 1d9fb179..f1acceda 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -1,4 +1,5 @@
 environment:
+  RUST_BACKTRACE: full
   TREE_SITTER_TEST: true
 
 build: false
diff --git a/.travis.yml b/.travis.yml
index 47b88e81..46bb9a95 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ rust:
 
 env:
   - TREE_SITTER_TEST=1
+  - RUST_BACKTRACE=full
 
 before_install:
   - ./script/fetch-fixtures