diff --git a/.cargo/config.toml b/.cargo/config.toml
index b3e368cb6..91d9f29d2 100644
--- a/.cargo/config.toml
+++ b/.cargo/config.toml
@@ -34,4 +34,8 @@ rustflags = [
 # compiling this crate in release on Windows/macOS.
 [env]
 RUST_MIN_STACK = "67108864"
+# UI tests render through iced_test, which picks wgpu by default. Several
+# test threads opening GPU devices at once crash the driver (SIGSEGV, about
+# every other parallel `cargo test` run); the software renderer is safe.
+ICED_TEST_BACKEND = "tiny-skia"