diff --git a/.bazelrc b/.bazelrc
new file mode 100644
index 000000000..1f52e460b
--- /dev/null
+++ b/.bazelrc
@@ -0,0 +1,4 @@
+# Since there's no way to set the deployment version for swift_{binary,test},
+# this forces all targets' minimum macOS to Catalina until Bazel CI has
+# upgraded their Mac machines to Big Sur.
+build --macos_minimum_os=10.15