diff --git a/ChangeLog b/ChangeLog
index faee4cfdd..bdccb3669 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2003-08-12  Moritz Bunkus  <moritz@bunkus.org>
 
+        * Windows versions: Fixed a bug with files bigger than 2GB not
+        being recognized. The accompanying error message was "File NAME
+        has unknown type. Please have a look at the supported file
+        types..."
+
         * all tools: Fixed a bug which would only allow Matroska files up
         to 4GB to be read. The accompanying error message was "No segment
         found" or something similar.
diff --git a/src/base64tool.cpp b/src/base64tool.cpp
index b8d0208a5..4ec62800f 100644
--- a/src/base64tool.cpp
+++ b/src/base64tool.cpp
@@ -43,7 +43,7 @@ void usage(int retval) {
 
 int main(int argc, char *argv[]) {
   int maxlen;
-  int64_t size;
+  uint64_t size;
   unsigned char *buffer;
   char mode;
   string s, line;
diff --git a/src/mkvmerge.cpp b/src/mkvmerge.cpp
index 7acd14934..1af9a1149 100644
--- a/src/mkvmerge.cpp
+++ b/src/mkvmerge.cpp
@@ -309,7 +309,7 @@ static void usage() {
 static int get_type(char *filename) {
   mm_io_c *mm_io;
   mm_text_io_c *mm_text_io;
-  off_t size;
+  uint64_t size;
   int type;
 
   try {
diff --git a/src/mm_io.cpp b/src/mm_io.cpp
index b6571e011..b5634c581 100644
--- a/src/mm_io.cpp
+++ b/src/mm_io.cpp
@@ -166,8 +166,10 @@ uint64 mm_io_c::getFilePointer() {
   DWORD low;
   
   low = SetFilePointer((HANDLE)file, 0, &high, FILE_CURRENT);
-  if ((low == INVALID_SET_FILE_POINTER) && (GetLastError() != NO_ERROR))
+  if ((low == INVALID_SET_FILE_POINTER) && (GetLastError() != NO_ERROR)) {
+    printf("nonono\n");
     return (uint64)-1;
+  }
 
   return (((uint64)high) << 32) | (uint64)low;
 }
@@ -188,8 +190,8 @@ void mm_io_c::setFilePointer(int64 offset, seek_mode mode) {
       break;
   }
 
-  high = offset >> 32;
-  SetFilePointer((HANDLE)file, offset & 0xffffffff, &high, method);
+  high = (LONG)(offset >> 32);
+  SetFilePointer((HANDLE)file, (LONG)(offset & 0xffffffff), &high, method);
 }
 
 uint32 mm_io_c::read(void *buffer, size_t size) {