diff --git a/src/Cargo.toml b/src/Cargo.toml
index be4db9d3e2aa0..5ae26fea2d13b 100644
--- a/src/Cargo.toml
+++ b/src/Cargo.toml
@@ -40,6 +40,13 @@ members = [
   "tools/rls/test_data/workspace_symbol",
 ]
 
+# Curiously, LLVM 7.0 will segfault if compiled with opt-level=3
+# See issue https://github.com/rust-lang/rust/issues/52378
+[profile.release]
+opt-level = 2
+[profile.bench]
+opt-level = 2
+
 # These options are controlled from our rustc wrapper script, so turn them off
 # here and have them controlled elsewhere.
 [profile.dev]