diff --git a/Source/build.cpp b/Source/build.cpp
index 9b1e7bb5..52a917c8 100644
--- a/Source/build.cpp
+++ b/Source/build.cpp
@@ -794,9 +794,8 @@ int CEXEBuild::add_db_data(IMMap *mmap) // returns offset
   {
     // grow datablock so that there is room to compress into
     int bufferlen = length + 1024 + length / 4; // give a nice 25% extra space
-    if (bufferlen < 0) // too much data... try allocating as much as possible
-      db->resize(max(st, 0x7fffffff));
-    else
+    if (st+bufferlen+sizeof(int) < 0)          // we've hit a signed integer overflow (file is over 1.6 GB)
+        bufferlen = INT_MAX-st-sizeof(int); //  so maximize compressor room and hope the file compresses well
       db->resize(st + bufferlen + sizeof(int));
 
     int n = compressor->Init(build_compress_level, build_compress_dict_size);
@@ -2354,7 +2353,7 @@ int CEXEBuild::UpdatePEHeader()
 
 void CEXEBuild::set_default_output_filename(const tstring& filename)
 {
-    if (build_output_filename[0] == 0)
+    if (build_output_filename[0] == 0)
         _tcsnccpy(build_output_filename,filename.c_str(),1024-1);
 }
 
diff --git a/Source/mmap.cpp b/Source/mmap.cpp
index 29623933..787bc6be 100644
--- a/Source/mmap.cpp
+++ b/Source/mmap.cpp
@@ -336,7 +336,7 @@ void MMapFile::flush(int num)
 {
   if (m_pView)
 #ifdef _WIN32
-    FlushViewOfFile(m_pView, num);
+  {} // improving performance by commenting: FlushViewOfFile(m_pView, num);
 #else
     msync((char *)m_pView, num, MS_SYNC);
 #endif
@@ -431,6 +431,8 @@ void MMapBuf::resize(int newlen)
   if (newlen > m_alloc)
   {
     m_alloc = newlen + (16 << 20); // add 16mb to top of mapping
+    if (m_alloc < 0) // we've hit a signed integer overflow
+        m_alloc = INT_MAX;
 
     m_fm.resize(m_alloc);