diff --git a/sim/mcuboot-sys/Cargo.toml b/sim/mcuboot-sys/Cargo.toml
index c678082..225ca0c 100644
--- a/sim/mcuboot-sys/Cargo.toml
+++ b/sim/mcuboot-sys/Cargo.toml
@@ -91,8 +91,3 @@
 libc = "0.2"
 log = "0.4"
 simflash = { path = "../simflash" }
-
-# Optimize some, even when building for debugging, otherwise the tests
-# are too slow.
-[profile.test]
-opt-level = 1