diff --git a/konan/konan.properties b/konan/konan.properties
index 5e2fff6e7c0..12f6597bf59 100644
--- a/konan/konan.properties
+++ b/konan/konan.properties
@@ -28,7 +28,7 @@ downloadingAttempts = 10
 downloadingAttemptIntervalMs = 3000
 homeDependencyCache = .konan/cache
 
-llvmDebugOptFlags = -O0
+llvmDebugOptFlags = -O1
 llvmVersion = 5.0.0
 
 # Mac OS X.