diff --git a/lib/mfile.cpp b/lib/mfile.cpp
index d6fed85187..e459ec21c5 100644
--- a/lib/mfile.cpp
+++ b/lib/mfile.cpp
@@ -57,8 +57,12 @@ int MFILE::open(const char* path, const char* mode) {
 // seems like Win's realloc is stupid,  Make it smart.
 //
 static inline char* realloc_aux(char* p, int len) {
+#ifdef _WIN32
     if (_msize(p) >= len) return p;
     return (char*) realloc(p, len*2);
+#else
+    return (char*) realloc(p, len);
+#endif
 }
 
 #define BUFSIZE 100000