diff --git a/minisat/utils/ParseUtils.h b/minisat/utils/ParseUtils.h
index d3071649..f31fb9ec 100644
--- a/minisat/utils/ParseUtils.h
+++ b/minisat/utils/ParseUtils.h
@@ -26,27 +26,34 @@ OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWA
 
 #include <zlib.h>
 
+#include "minisat/mtl/XAlloc.h"
+
 namespace Minisat {
 
 //-------------------------------------------------------------------------------------------------
 // A simple buffered character stream class:
 
-static const int buffer_size = 1048576;
 
 
 class StreamBuffer {
-    gzFile        in;
-    unsigned char buf[buffer_size];
-    int           pos;
-    int           size;
+    gzFile         in;
+    unsigned char* buf;
+    int            pos;
+    int            size;
+
+    enum { buffer_size = 64*1024 };
 
     void assureLookahead() {
         if (pos >= size) {
             pos  = 0;
-            size = gzread(in, buf, sizeof(buf)); } }
+            size = gzread(in, buf, buffer_size); } }
 
 public:
-    explicit StreamBuffer(gzFile i) : in(i), pos(0), size(0) { assureLookahead(); }
+    explicit StreamBuffer(gzFile i) : in(i), pos(0), size(0){
+        buf = (unsigned char*)xrealloc(NULL, buffer_size);
+        assureLookahead();
+    }
+    ~StreamBuffer() { free(buf); }
 
     int  operator *  () const { return (pos >= size) ? EOF : buf[pos]; }
     void operator ++ ()       { pos++; assureLookahead(); }