diff --git a/src/bin/pg_test_fsync/pg_test_fsync.c b/src/bin/pg_test_fsync/pg_test_fsync.c
index c607b5371c0..dfe1991d551 100644
--- a/src/bin/pg_test_fsync/pg_test_fsync.c
+++ b/src/bin/pg_test_fsync/pg_test_fsync.c
@@ -223,7 +223,7 @@ test_open(void)
 	/*
 	 * test if we can open the target file
 	 */
-	if ((tmpfile = open(filename, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR)) == -1)
+	if ((tmpfile = open(filename, O_RDWR | O_CREAT | PG_BINARY, S_IRUSR | S_IWUSR)) == -1)
 		die("could not open output file");
 	needs_unlink = 1;
 	if (write(tmpfile, full_buf, XLOG_SEG_SIZE) != XLOG_SEG_SIZE)
@@ -257,7 +257,7 @@ test_sync(int writes_per_op)
 	fflush(stdout);
 
 #ifdef OPEN_DATASYNC_FLAG
-	if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT, 0)) == -1)
+	if ((tmpfile = open(filename, O_RDWR | O_DSYNC | PG_O_DIRECT | PG_BINARY, 0)) == -1)
 	{
 		printf(NA_FORMAT, _("n/a*"));
 		fs_warning = true;
@@ -287,7 +287,7 @@ test_sync(int writes_per_op)
 	fflush(stdout);
 
 #ifdef HAVE_FDATASYNC
-	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+	if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
 		die("could not open output file");
 	START_TIMER;
 	for (ops = 0; alarm_triggered == false; ops++)
@@ -311,7 +311,7 @@ test_sync(int writes_per_op)
 	printf(LABEL_FORMAT, "fsync");
 	fflush(stdout);
 
-	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+	if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
 		die("could not open output file");
 	START_TIMER;
 	for (ops = 0; alarm_triggered == false; ops++)
@@ -334,7 +334,7 @@ test_sync(int writes_per_op)
 	fflush(stdout);
 
 #ifdef HAVE_FSYNC_WRITETHROUGH
-	if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+	if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
 		die("could not open output file");
 	START_TIMER;
 	for (ops = 0; alarm_triggered == false; ops++)
@@ -360,7 +360,7 @@ test_sync(int writes_per_op)
 	fflush(stdout);
 
 #ifdef OPEN_SYNC_FLAG
-	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT, 0)) == -1)
+	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT | PG_BINARY, 0)) == -1)
 	{
 		printf(NA_FORMAT, _("n/a*"));
 		fs_warning = true;
@@ -427,7 +427,7 @@ test_open_sync(const char *msg, int writes_size)
 	fflush(stdout);
 
 #ifdef OPEN_SYNC_FLAG
-	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT, 0)) == -1)
+	if ((tmpfile = open(filename, O_RDWR | OPEN_SYNC_FLAG | PG_O_DIRECT | PG_BINARY, 0)) == -1)
 		printf(NA_FORMAT, _("n/a*"));
 	else
 	{
@@ -475,7 +475,7 @@ test_file_descriptor_sync(void)
 	START_TIMER;
 	for (ops = 0; alarm_triggered == false; ops++)
 	{
-		if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
 			die("could not open output file");
 		if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 			die("write failed");
@@ -487,7 +487,7 @@ test_file_descriptor_sync(void)
 		 * open and close the file again to be consistent with the following
 		 * test
 		 */
-		if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
 			die("could not open output file");
 		close(tmpfile);
 	}
@@ -503,13 +503,13 @@ test_file_descriptor_sync(void)
 	START_TIMER;
 	for (ops = 0; alarm_triggered == false; ops++)
 	{
-		if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
 			die("could not open output file");
 		if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 			die("write failed");
 		close(tmpfile);
 		/* reopen file */
-		if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
 			die("could not open output file");
 		if (fsync(tmpfile) != 0)
 			die("fsync failed");
@@ -534,7 +534,7 @@ test_non_sync(void)
 	START_TIMER;
 	for (ops = 0; alarm_triggered == false; ops++)
 	{
-		if ((tmpfile = open(filename, O_RDWR, 0)) == -1)
+		if ((tmpfile = open(filename, O_RDWR | PG_BINARY, 0)) == -1)
 			die("could not open output file");
 		if (write(tmpfile, buf, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 			die("write failed");