diff --git a/Makefile b/Makefile
index 678b3b3..fcef49f 100644
--- a/Makefile
+++ b/Makefile
@@ -40,6 +40,7 @@ SRCS	= libunwind.c \
 		Lset_fpreg.c \
 		Lset_reg.c \
 		mempool.c \
-		strerror.c
+		strerror.c \
+		 malloc_types.c
 
 .include <bsd.kmod.mk>
diff --git a/flush_cache.c b/flush_cache.c
index 966f353..c865227 100644
--- a/flush_cache.c
+++ b/flush_cache.c
@@ -36,8 +36,8 @@ unw_flush_cache (unw_addr_space_t as, unw_word_t lo, unw_word_t hi)
   for (; w; w = w->next)
     {
       if (w->index)
-        free (w->index);
-      free (w->debug_frame);
+        free (w->index, M_LIBUNWIND_TYPE);
+      free (w->debug_frame, M_LIBUNWIND_TYPE);
     }
   as->debug_frames = NULL;
 
diff --git a/include/libunwind_i.h b/include/libunwind_i.h
index 85fb05e..5ad817f 100644
--- a/include/libunwind_i.h
+++ b/include/libunwind_i.h
@@ -94,6 +94,7 @@ do {									\
 #define mutex_unlock(l)							\
 	sx_unlock(l)
 
+MALLOC_DECLARE(M_LIBUNWIND_TYPE);
 
 static inline int
 cmpxchg_ptr (void *addr, void *old, void *new)
diff --git a/malloc_types.c b/malloc_types.c
new file mode 100644
index 0000000..4904c25
--- /dev/null
+++ b/malloc_types.c
@@ -0,0 +1,4 @@
+#include <sys/malloc.h>
+
+MALLOC_DEFINE(M_LIBUNWIND_TYPE, "libunwind allocations", "Libunwind "
+              "Allocations");
\ No newline at end of file