diff --git a/libc/include/sys/cdefs.h b/libc/include/sys/cdefs.h
index 342cfad..f51942b 100644
--- a/libc/include/sys/cdefs.h
+++ b/libc/include/sys/cdefs.h
@@ -462,8 +462,8 @@
 #define __size_mul_overflow(a, b, result) __builtin_umul_overflow(a, b, result)
 #endif
 #else
-static __inline__ __always_inline int __size_mul_overflow(__SIZE_TYPE__ a, __SIZE_TYPE__ b,
-                                                          __SIZE_TYPE__ *result) {
+extern __inline__ __always_inline __attribute__((gnu_inline))
+int __size_mul_overflow(__SIZE_TYPE__ a, __SIZE_TYPE__ b, __SIZE_TYPE__ *result) {
     *result = a * b;
     static const __SIZE_TYPE__ mul_no_overflow = 1UL << (sizeof(__SIZE_TYPE__) * 4);
     return (a >= mul_no_overflow || b >= mul_no_overflow) && a > 0 && (__SIZE_TYPE__)-1 / a < b;
diff --git a/libc/malloc_debug/malloc_debug.h b/libc/malloc_debug/malloc_debug.h
index cd025a7..6f9f90f 100644
--- a/libc/malloc_debug/malloc_debug.h
+++ b/libc/malloc_debug/malloc_debug.h
@@ -58,11 +58,6 @@
   static size_t max_size() { return (1U << 31) - 1; }
 } __attribute__((packed));
 
-struct TrackHeader {
-  Header* prev = nullptr;
-  Header* next = nullptr;
-} __attribute__((packed));
-
 struct BacktraceHeader {
   size_t num_frames;
   uintptr_t frames[0];
diff --git a/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp b/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
index 4b8aaeb..9fc8a57 100644
--- a/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
+++ b/libc/malloc_debug/tests/malloc_debug_unit_tests.cpp
@@ -67,14 +67,10 @@
 constexpr char DIVIDER[] =
     "6 malloc_debug *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***\n";
 
-constexpr uint32_t TRACK_HEADER = 0x2;
-constexpr uint32_t BACKTRACE_HEADER = 0x4;
+constexpr uint32_t BACKTRACE_HEADER = 0x1;
 
 static size_t get_tag_offset(uint32_t flags = 0, size_t backtrace_frames = 0) {
   size_t offset = BIONIC_ALIGN(sizeof(Header), sizeof(uintptr_t));
-  if (flags & TRACK_HEADER) {
-    offset += BIONIC_ALIGN(sizeof(TrackHeader), sizeof(uintptr_t));
-  }
   if (flags & BACKTRACE_HEADER) {
     offset += BIONIC_ALIGN(sizeof(BacktraceHeader) + sizeof(uintptr_t) * backtrace_frames, sizeof(uintptr_t));
   }