diff --git a/src/coreclr/pal/src/init/pal.cpp b/src/coreclr/pal/src/init/pal.cpp
index f7a0cef45a5db9..64fffbef6e0f2e 100644
--- a/src/coreclr/pal/src/init/pal.cpp
+++ b/src/coreclr/pal/src/init/pal.cpp
@@ -248,7 +248,7 @@ EnsureStackSize(SIZE_T stackSize)
 void
 InitializeDefaultStackSize()
 {
-    CLRConfigNoCache defStackSize = CLRConfigNoCache::Get("DefaultStackSize", /*noprefix*/ false, &getenv);
+    CLRConfigNoCache defStackSize = CLRConfigNoCache::Get("Thread_DefaultStackSize", /*noprefix*/ false, &getenv);
     if (defStackSize.IsSet())
     {
         DWORD size;