1 files changed, 1 insertions, 1 deletions
diff --git a/perform/iopipe.c b/perform/iopipe.c
index 88b0fe6..200ee7e 100644
--- a/perform/iopipe.c
+++ b/perform/iopipe.c
@@ -147,7 +147,7 @@ static void
 synchronize (void)
 {
 #ifdef H5_HAVE_SYSTEM
-#ifdef WIN32
+#if defined(WIN32) && ! defined(__CYGWIN__)
 	_flushall();
 #else
     HDsystem ("sync");