diff --git a/mimetic/os/mmfile.cxx b/mimetic/os/mmfile.cxx
index dfc95b7..3e54a53 100644
--- a/mimetic/os/mmfile.cxx
+++ b/mimetic/os/mmfile.cxx
@@ -57,7 +57,7 @@ bool MMFile::open(int mode)
 bool MMFile::map()
 {
     m_beg = (char*) mmap(0, m_st.st_size, PROT_READ, MAP_SHARED,m_fd,0);
-    if(m_beg > 0)
+    if(m_beg != 0)
     {
         m_end = m_beg + m_st.st_size;
         #if HAVE_MADVISE