diff --git a/libc/bionic/malloc_common.cpp b/libc/bionic/malloc_common.cpp
index 38168ee..9744968 100644
--- a/libc/bionic/malloc_common.cpp
+++ b/libc/bionic/malloc_common.cpp
@@ -326,12 +326,12 @@
     return LimitEnable(arg, arg_size);
   }
   if (opcode == M_INITIALIZE_GWP_ASAN) {
-    if (arg == nullptr || arg_size != sizeof(bool)) {
+    if (arg == nullptr || arg_size != sizeof(android_mallopt_gwp_asan_options_t)) {
       errno = EINVAL;
       return false;
     }
 
-    return EnableGwpAsan(*reinterpret_cast<bool*>(arg));
+    return EnableGwpAsan(*reinterpret_cast<android_mallopt_gwp_asan_options_t*>(arg));
   }
   errno = ENOTSUP;
   return false;