diff --git a/include/wx/defs.h b/include/wx/defs.h
index 148e9c2fbc..780acae232 100644
--- a/include/wx/defs.h
+++ b/include/wx/defs.h
@@ -1018,6 +1018,9 @@ inline void *wxUIntToPtr(wxUIntPtr p)
     #else
         #error "error defining ssize_t, size_t is not 4 or 8 bytes"
     #endif
+
+    /* prevent ssize_t redefinitions in other libraries */
+    #define HAVE_SSIZE_T
 #endif