diff --git a/ddprof-lib/src/main/cpp/threadFilter.cpp b/ddprof-lib/src/main/cpp/threadFilter.cpp
index 5662c45d..034aabf9 100644
--- a/ddprof-lib/src/main/cpp/threadFilter.cpp
+++ b/ddprof-lib/src/main/cpp/threadFilter.cpp
@@ -43,6 +43,9 @@ ThreadFilter::~ThreadFilter() {
       OS::safeFree(_bitmap[i], BITMAP_SIZE);
     }
   }
+  if (_bitmap) {
+    OS::safeFree(_bitmap, _max_bitmaps * sizeof(u64 *));
+  }
 }
 
 void ThreadFilter::init(const char *filter) {