diff --git a/lib/defines.h b/lib/defines.h
index ee291a43..0939a968 100644
--- a/lib/defines.h
+++ b/lib/defines.h
@@ -49,3 +49,15 @@ static const char * DBG_LVL_LIST[] = {"NONE", "FAIL", "ERROR", "WARN", "INFO", "
 #define INFO_MSG(msg, ...) DEBUG_MSG(DLVL_DEVEL, msg, ##__VA_ARGS__)
 
 #endif
+
+/// The size used for stream header pages under Windows, where they cannot be size-detected.
+#define DEFAULT_META_PAGE_SIZE 16 * 1024 * 1024
+
+/// The size used for stream data pages under Windows, where they cannot be size-detected.
+#define DEFAULT_DATA_PAGE_SIZE 25 * 1024 * 1024
+
+/// The size used for server configuration pages.
+#define DEFAULT_CONF_PAGE_SIZE 4 * 1024 * 1024
+
+/// The position from where on stream data pages are switched over to the next page.
+#define FLIP_DATA_PAGE_SIZE 8 * 1024 * 1024
diff --git a/lib/stream.cpp b/lib/stream.cpp
index 36d944b4..1300a0c7 100644
--- a/lib/stream.cpp
+++ b/lib/stream.cpp
@@ -71,7 +71,7 @@ void Util::sanitizeName(std::string & streamname) {
 
 /// Starts a process for a VoD stream.
 bool Util::startInput(std::string streamname, std::string filename, bool forkFirst) {
-  IPC::sharedPage mistConfOut("!mistConfig", 4*1024*1024);
+  IPC::sharedPage mistConfOut("!mistConfig", DEFAULT_CONF_PAGE_SIZE);
   IPC::semaphore configLock("!mistConfLock", O_CREAT | O_RDWR, ACCESSPERMS, 1);
   configLock.wait();
   DTSC::Scan config = DTSC::Scan(mistConfOut.mapped, mistConfOut.len);