diff --git a/linker/linker_cfi.cpp b/linker/linker_cfi.cpp
index e9cdab6..28d2eaf 100644
--- a/linker/linker_cfi.cpp
+++ b/linker/linker_cfi.cpp
@@ -193,6 +193,7 @@
   shadow_start = reinterpret_cast<uintptr_t* (*)(uintptr_t)>(cfi_init)(p);
   CHECK(shadow_start != nullptr);
   CHECK(*shadow_start == p);
+  mprotect(shadow_start, PAGE_SIZE, PROT_READ);
   return true;
 }