diff --git a/guarded_pool_allocator.cpp b/guarded_pool_allocator.cpp
index 86304d9..5e3455e 100644
--- a/guarded_pool_allocator.cpp
+++ b/guarded_pool_allocator.cpp
@@ -103,9 +103,15 @@
     installAtFork();
 }
 
-void GuardedPoolAllocator::disable() { PoolMutex.lock(); }
+void GuardedPoolAllocator::disable() {
+  PoolMutex.lock();
+  BacktraceMutex.lock();
+}
 
-void GuardedPoolAllocator::enable() { PoolMutex.unlock(); }
+void GuardedPoolAllocator::enable() {
+  PoolMutex.unlock();
+  BacktraceMutex.unlock();
+}
 
 void GuardedPoolAllocator::iterate(void *Base, size_t Size, iterate_callback Cb,
                                    void *Arg) {
@@ -232,7 +238,10 @@
       roundUpTo(Size, PageSize));
 
   Meta->RecordAllocation(UserPtr, Size);
-  Meta->AllocationTrace.RecordBacktrace(Backtrace);
+  {
+    ScopedLock UL(BacktraceMutex);
+    Meta->AllocationTrace.RecordBacktrace(Backtrace);
+  }
 
   return reinterpret_cast<void *>(UserPtr);
 }
@@ -281,6 +290,7 @@
     // otherwise non-reentrant unwinders may deadlock.
     if (!getThreadLocals()->RecursiveGuard) {
       ScopedRecursiveGuard SRG;
+      ScopedLock UL(BacktraceMutex);
       Meta->DeallocationTrace.RecordBacktrace(Backtrace);
     }
   }
diff --git a/guarded_pool_allocator.h b/guarded_pool_allocator.h
index 86521f9..26a4599 100644
--- a/guarded_pool_allocator.h
+++ b/guarded_pool_allocator.h
@@ -196,6 +196,10 @@
 
   // A mutex to protect the guarded slot and metadata pool for this class.
   Mutex PoolMutex;
+  // Some unwinders can grab the libdl lock. In order to provide atfork
+  // protection, we need to ensure that we allow an unwinding thread to release
+  // the libdl lock before forking.
+  Mutex BacktraceMutex;
   // Record the number allocations that we've sampled. We store this amount so
   // that we don't randomly choose to recycle a slot that previously had an
   // allocation before all the slots have been utilised.