diff --git a/src/common/zstream.cpp b/src/common/zstream.cpp
index 6c1a0c423d..5372d21481 100644
--- a/src/common/zstream.cpp
+++ b/src/common/zstream.cpp
@@ -57,12 +57,7 @@ wxZlibInputStream::wxZlibInputStream(wxInputStream& stream, int flags)
     m_inflate = new z_stream_s;
 
     if (m_inflate) {
-      m_inflate->zalloc = (alloc_func)0;
-      m_inflate->zfree = (free_func)0;
-      m_inflate->opaque = (voidpf)0;
-      m_inflate->avail_in = 0;
-      m_inflate->next_in = NULL;
-      m_inflate->next_out = NULL;
+      memset(m_inflate, 0, sizeof(z_stream_s));
 
       wxASSERT((flags & ~(wxZLIB_ZLIB | wxZLIB_GZIP)) == 0);
  
@@ -171,10 +166,7 @@ wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream,
      m_deflate = new z_stream_s;
 
      if (m_deflate) {
-        m_deflate->zalloc = (alloc_func)0;
-        m_deflate->zfree = (free_func)0;
-        m_deflate->opaque = (voidpf)0;
-        m_deflate->avail_in = 0;
+        memset(m_deflate, 0, sizeof(z_stream_s));
         m_deflate->next_out = m_z_buffer;
         m_deflate->avail_out = m_z_size;