diff --git a/tools/libclang/CIndex.cpp b/tools/libclang/CIndex.cpp
index e24a622..30d1c28 100644
--- a/tools/libclang/CIndex.cpp
+++ b/tools/libclang/CIndex.cpp
@@ -4431,7 +4431,8 @@
 // Misc. utility functions.
 //===----------------------------------------------------------------------===//
 
-static unsigned SafetyStackThreadSize = 0;
+/// Default to using an 8 MB stack size on "safety" threads.
+static unsigned SafetyStackThreadSize = 8 << 20;
 
 namespace clang {