diff --git third_party/blink/renderer/platform/heap/thread_local.h third_party/blink/renderer/platform/heap/thread_local.h
index 84ef4350bd96d..dbd5b0b73ebb2 100644
--- third_party/blink/renderer/platform/heap/thread_local.h
+++ third_party/blink/renderer/platform/heap/thread_local.h
@@ -36,7 +36,7 @@
 #if BLINK_HEAP_HIDE_THREAD_LOCAL_IN_LIBRARY
 #define BLINK_HEAP_THREAD_LOCAL_MODEL "local-dynamic"
 #else
-#if defined(OS_WIN)
+#if defined(OS_WIN) || (defined(OS_POSIX) && !defined(OS_MAC))
 #define BLINK_HEAP_THREAD_LOCAL_MODEL "initial-exec"
 #elif defined(OS_ANDROID)
 #define BLINK_HEAP_THREAD_LOCAL_MODEL "local-dynamic"