diff --git a/miniz_tinfl.c b/miniz_tinfl.c
index 69c3f2d..6e9849f 100644
--- a/miniz_tinfl.c
+++ b/miniz_tinfl.c
@@ -699,6 +699,7 @@ int tinfl_decompress_mem_to_callback(const void *pIn_buf, size_t *pIn_buf_size,
     size_t in_buf_ofs = 0, dict_ofs = 0;
     if (!pDict)
         return TINFL_STATUS_FAILED;
+    memset(pDict,0,TINFL_LZ_DICT_SIZE);
     tinfl_init(&decomp);
     for (;;)
     {