--- a/runtime/allocator.cpp
+++ b/runtime/allocator.cpp
@@ -9,6 +9,36 @@
 #include <dlfcn.h>
 #include <unistd.h>
 
+static void *(* volatile malloc_hook_dummy)(size_t, const void *);
+static decltype(malloc_hook_dummy) *malloc_hook_ptr;
+static void *(* volatile realloc_hook_dummy)(void *, size_t, const void *);
+static decltype(realloc_hook_dummy) *realloc_hook_ptr;
+static void (* volatile free_hook_dummy)(void *, const void *);
+static decltype(free_hook_dummy) *free_hook_ptr;
+static void *(* volatile memalign_hook_dummy)(size_t, size_t, const void *);
+static decltype(memalign_hook_dummy) *memalign_hook_ptr;
+
+static void malloc_hook_init(void) {
+  static bool initialized = false;
+  if (initialized) return;
+  void *libc_handle = dlopen("libc.so", RTLD_NOW);
+  if (libc_handle != NULL) {
+    malloc_hook_ptr = (decltype(malloc_hook_ptr))dlsym(libc_handle, "__malloc_hook");
+    realloc_hook_ptr = (decltype(realloc_hook_ptr))dlsym(libc_handle, "__realloc_hook");
+    free_hook_ptr = (decltype(free_hook_ptr))dlsym(libc_handle, "__free_hook");
+    memalign_hook_ptr = (decltype(memalign_hook_ptr))dlsym(libc_handle, "__memalign_hook");
+  }
+  if (malloc_hook_ptr == NULL)
+    malloc_hook_ptr = &malloc_hook_dummy;
+  if (realloc_hook_ptr == NULL)
+    realloc_hook_ptr = &realloc_hook_dummy;
+  if (free_hook_ptr == NULL)
+    free_hook_ptr = &free_hook_dummy;
+  if (memalign_hook_ptr == NULL)
+    memalign_hook_ptr = &memalign_hook_dummy;
+  initialized = true;
+}
+
 #include "common/algorithms/find.h"
 #include "common/containers/final_action.h"
 #include "common/macos-ports.h"
@@ -246,10 +276,11 @@
   void switch_hooks(bool malloc_hooks_are_replaced_before) noexcept {
     php_assert(malloc_hooks_are_replaced_before == malloc_hooks_are_replaced_);
     CriticalSectionGuard critical_section;
-    std::swap(malloc_hook_, __malloc_hook);
-    std::swap(realloc_hook_, __realloc_hook);
-    std::swap(memalign_hook_, __memalign_hook);
-    std::swap(free_hook_, __free_hook);
+    malloc_hook_init();
+    std::swap(malloc_hook_, *malloc_hook_ptr);
+    std::swap(realloc_hook_, *realloc_hook_ptr);
+    std::swap(memalign_hook_, *memalign_hook_ptr);
+    std::swap(free_hook_, *free_hook_ptr);
     malloc_hooks_are_replaced_ = !malloc_hooks_are_replaced_;
   }
 
@@ -274,10 +305,10 @@
       return script_allocator_free(ptr);
     }} {}
 
-  decltype(__malloc_hook) malloc_hook_{nullptr};
-  decltype(__realloc_hook) realloc_hook_{nullptr};
-  decltype(__memalign_hook) memalign_hook_{nullptr};
-  decltype(__free_hook) free_hook_{nullptr};
+  decltype(malloc_hook_dummy) malloc_hook_{nullptr};
+  decltype(realloc_hook_dummy) realloc_hook_{nullptr};
+  decltype(memalign_hook_dummy) memalign_hook_{nullptr};
+  decltype(free_hook_dummy) free_hook_{nullptr};
   bool malloc_hooks_are_replaced_{false};
 };