diff --git a/.gitignore b/.gitignore
index 8012a26..0216f06 100644
--- a/.gitignore
+++ b/.gitignore
@@ -46,16 +46,15 @@
 .vscode
 .history
 
+# https://github.com/Dart-Code/Dart-Code/issues/1295
+/analysis_options.yaml
+
 # analysis server files
-analysis_options.yaml
 compile_commands.json
 
 # GDB files
 .gdb_history
 
-# https://github.com/Dart-Code/Dart-Code/issues/1295
-analysis_options.yaml
-
 # Built by chromebot and downloaded from Google Storage
 client/tests/drt
 
diff --git a/pkg/test_runner/analysis_options.yaml b/pkg/test_runner/analysis_options.yaml
new file mode 100644
index 0000000..1a46de2
--- /dev/null
+++ b/pkg/test_runner/analysis_options.yaml
@@ -0,0 +1,3 @@
+analyzer:
+  strong-mode:
+    implicit-casts: false