diff --git a/ChangeLog b/ChangeLog
index 8660448b..2f6b12d1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -12,6 +12,7 @@
 - block zero width or height images from imagemagick load [Koen1999]
 - check for overflow in gifload height [lovell]
 - fix msb_first default in ppm load and save [ewelot]
+- force binary mode on win for connection read / write [Alreiber]
 
 6/9/20 started 8.10.2
 - update magicksave/load profile handling [kelilevi]
diff --git a/libvips/iofuncs/source.c b/libvips/iofuncs/source.c
index 4989e458..224baeb8 100644
--- a/libvips/iofuncs/source.c
+++ b/libvips/iofuncs/source.c
@@ -7,6 +7,9 @@
  * 	- add vips_pipe_read_limit_set()
  * 3/10/20
  * 	- improve behaviour with read and seek on pipes
+ * 26/11/20
+ * 	- use _setmode() on win to force binary read for previously opened
+ * 	  descriptors
  */
 
 /*
@@ -62,6 +65,9 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#ifdef OS_WIN32
+#include <io.h>
+#endif /*OS_WIN32*/
 
 #include <vips/vips.h>
 #include <vips/internal.h>
@@ -300,6 +306,13 @@ vips_source_build( VipsObject *object )
 	if( vips_object_argument_isset( object, "descriptor" ) ) {
 		connection->descriptor = dup( connection->descriptor );
 		connection->close_descriptor = connection->descriptor;
+
+#ifdef OS_WIN32
+		/* Windows will create eg. stdin and stdout in text mode.
+		 * We always read in binary mode.
+		 */
+		_setmode( connection->descriptor, _O_BINARY );
+#endif /*OS_WIN32*/
 	}
 
 	if( vips_object_argument_isset( object, "blob" ) ) {
diff --git a/libvips/iofuncs/target.c b/libvips/iofuncs/target.c
index 1ca37835..01b3339c 100644
--- a/libvips/iofuncs/target.c
+++ b/libvips/iofuncs/target.c
@@ -2,6 +2,10 @@
  * socket, node.js stream, etc.
  * 
  * J.Cupitt, 19/6/14
+ *
+ * 26/11/20
+ * 	- use _setmode() on win to force binary write for previously opened
+ * 	  descriptors
  */
 
 /*
@@ -51,6 +55,9 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
+#ifdef OS_WIN32
+#include <io.h>
+#endif /*OS_WIN32*/
 
 #include <vips/vips.h>
 #include <vips/internal.h>
@@ -135,10 +142,16 @@ vips_target_build( VipsObject *object )
 	else if( vips_object_argument_isset( object, "descriptor" ) ) {
 		connection->descriptor = dup( connection->descriptor );
 		connection->close_descriptor = connection->descriptor;
+
+#ifdef OS_WIN32
+		/* Windows will create eg. stdin and stdout in text mode.
+		 * We always write in binary mode.
+		 */
+		_setmode( connection->descriptor, _O_BINARY );
+#endif /*OS_WIN32*/
 	}
-	else if( target->memory ) {
+	else if( target->memory ) 
 		target->memory_buffer = g_byte_array_new();
-	}
 
 	return( 0 );
 }