diff --git a/TODO b/TODO
index c01db248..79076033 100644
--- a/TODO
+++ b/TODO
@@ -3,7 +3,7 @@
 
 
 
-- add ore sequential mode readers
+- add more sequential mode readers
 
 	$ grep -l write_line *.c
 	csv.c
diff --git a/libvips/foreign/foreign.c b/libvips/foreign/foreign.c
index a938efb4..2b64d5bb 100644
--- a/libvips/foreign/foreign.c
+++ b/libvips/foreign/foreign.c
@@ -904,7 +904,7 @@ vips_foreign_load_class_init( VipsForeignLoadClass *class )
 		VIPS_ARGUMENT_REQUIRED_OUTPUT, 
 		G_STRUCT_OFFSET( VipsForeignLoad, out ) );
 
-	VIPS_ARG_ENUM( class, "flags", 6, 
+	VIPS_ARG_FLAGS( class, "flags", 6, 
 		_( "Flags" ), 
 		_( "Flags for this file" ),
 		VIPS_ARGUMENT_OPTIONAL_OUTPUT,
@@ -943,7 +943,8 @@ vips_foreign_tilecache( VipsImage *in, VipsImage **out, int strip_height )
 	vips_get_tile_size( in, &tile_width, &tile_height, &nlines );
 
 	/* We need two buffers, each with enough strips to make a complete
-	 * buffer. And double to be safe.
+	 * buffer. And double to be safe, since input buffers must be larger
+	 * than output, and our buffers may not align exactly.
 	 */
 	nstrips = 2 * (1 + nlines / strip_height); 
 
diff --git a/libvips/include/vips/foreign.h b/libvips/include/vips/foreign.h
index e1e9c15d..a16010e8 100644
--- a/libvips/include/vips/foreign.h
+++ b/libvips/include/vips/foreign.h
@@ -86,12 +86,12 @@ void *vips_foreign_map( const char *base,
 
 /* Image file load properties. 
  */
-typedef enum {
+typedef enum /*< flags >*/ {
 	VIPS_FOREIGN_NONE = 0,		/* No flags set */
 	VIPS_FOREIGN_PARTIAL = 1,	/* Lazy read OK (eg. tiled tiff) */
 	VIPS_FOREIGN_SEQUENTIAL = 2,	/* Top-to-bottom lazy read OK */
-	VIPS_FOREIGN_BIGENDIAN = 3,	/* Most-significant byte first */
-	VIPS_FOREIGN_ALL = 4		/* All flags set */
+	VIPS_FOREIGN_BIGENDIAN = 4,	/* Most-significant byte first */
+	VIPS_FOREIGN_ALL = 7		/* All flags set */
 } VipsForeignFlags;
 
 #define VIPS_TYPE_FOREIGN_LOAD (vips_foreign_load_get_type())
diff --git a/libvips/include/vips/object.h b/libvips/include/vips/object.h
index 6c7a899c..51c6f622 100644
--- a/libvips/include/vips/object.h
+++ b/libvips/include/vips/object.h
@@ -66,7 +66,7 @@ typedef struct _VipsObjectClass VipsObjectClass;
  * member of struct _VipsImage. We default its 'assigned' to TRUE
  * since the field is always set directly by C.
  */
-typedef enum {
+typedef enum /*< flags >*/ {
 	VIPS_ARGUMENT_NONE = 0,
 	VIPS_ARGUMENT_REQUIRED = 1,
 	VIPS_ARGUMENT_CONSTRUCT = 2,
@@ -201,6 +201,19 @@ extern int _vips__argument_id;
 		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
 }
 
+#define VIPS_ARG_FLAGS( CLASS, NAME, PRIORITY, LONG, DESC, \
+	FLAGS, OFFSET, TYPE, VALUE ) { \
+	GParamSpec *pspec; \
+	\
+	pspec = g_param_spec_flags( (NAME), (LONG), (DESC), \
+		(TYPE), (VALUE), \
+		G_PARAM_READWRITE );\
+	g_object_class_install_property( G_OBJECT_CLASS( CLASS ), \
+		_vips__argument_id++, pspec ); \
+	vips_object_class_install_argument( VIPS_OBJECT_CLASS( CLASS ), \
+		pspec, (FLAGS), (PRIORITY), (OFFSET) ); \
+}
+
 #define VIPS_ARG_STRING( CLASS, NAME, PRIORITY, LONG, DESC, FLAGS, OFFSET, \
 	VALUE ) { \
 	GParamSpec *pspec; \
diff --git a/libvips/iofuncs/enumtypes.c b/libvips/iofuncs/enumtypes.c
index 7bbaf637..c8eb8554 100644
--- a/libvips/iofuncs/enumtypes.c
+++ b/libvips/iofuncs/enumtypes.c
@@ -11,7 +11,7 @@ vips_foreign_flags_get_type( void )
 	static GType etype = 0;
 
 	if( etype == 0 ) {
-		static const GEnumValue values[] = {
+		static const GFlagsValue values[] = {
 			{VIPS_FOREIGN_NONE, "VIPS_FOREIGN_NONE", "none"},
 			{VIPS_FOREIGN_PARTIAL, "VIPS_FOREIGN_PARTIAL", "partial"},
 			{VIPS_FOREIGN_SEQUENTIAL, "VIPS_FOREIGN_SEQUENTIAL", "sequential"},
@@ -20,7 +20,7 @@ vips_foreign_flags_get_type( void )
 			{0, NULL, NULL}
 		};
 		
-		etype = g_enum_register_static( "VipsForeignFlags", values );
+		etype = g_flags_register_static( "VipsForeignFlags", values );
 	}
 
 	return( etype );
@@ -499,7 +499,7 @@ vips_argument_flags_get_type( void )
 	static GType etype = 0;
 
 	if( etype == 0 ) {
-		static const GEnumValue values[] = {
+		static const GFlagsValue values[] = {
 			{VIPS_ARGUMENT_NONE, "VIPS_ARGUMENT_NONE", "none"},
 			{VIPS_ARGUMENT_REQUIRED, "VIPS_ARGUMENT_REQUIRED", "required"},
 			{VIPS_ARGUMENT_CONSTRUCT, "VIPS_ARGUMENT_CONSTRUCT", "construct"},
@@ -510,7 +510,7 @@ vips_argument_flags_get_type( void )
 			{0, NULL, NULL}
 		};
 		
-		etype = g_enum_register_static( "VipsArgumentFlags", values );
+		etype = g_flags_register_static( "VipsArgumentFlags", values );
 	}
 
 	return( etype );
diff --git a/libvips/iofuncs/object.c b/libvips/iofuncs/object.c
index 984f49e1..e4faeb48 100644
--- a/libvips/iofuncs/object.c
+++ b/libvips/iofuncs/object.c
@@ -998,6 +998,12 @@ vips_object_set_property( GObject *gobject,
 
 		*member = g_value_get_enum( value );
 	}
+	else if( G_IS_PARAM_SPEC_FLAGS( pspec ) ) {
+		int *member = &G_STRUCT_MEMBER( int, object,
+			argument_class->offset );
+
+		*member = g_value_get_flags( value );
+	}
 	else if( G_IS_PARAM_SPEC_POINTER( pspec ) ) {
 		gpointer *member = &G_STRUCT_MEMBER( gpointer, object,
 			argument_class->offset );
@@ -1104,6 +1110,12 @@ vips_object_get_property( GObject *gobject,
 
 		g_value_set_enum( value, *member );
 	}
+	else if( G_IS_PARAM_SPEC_FLAGS( pspec ) ) {
+		int *member = &G_STRUCT_MEMBER( int, object,
+			argument_class->offset );
+
+		g_value_set_flags( value, *member );
+	}
 	else if( G_IS_PARAM_SPEC_POINTER( pspec ) ) {
 		gpointer *member = &G_STRUCT_MEMBER( gpointer, object,
 			argument_class->offset );
@@ -1497,6 +1509,12 @@ vips_object_set_argument_from_string( VipsObject *object,
 		g_value_init( &gvalue, otype );
 		g_value_set_enum( &gvalue, enum_value->value );
 	}
+	else if( G_IS_PARAM_SPEC_FLAGS( pspec ) ) {
+		/* Hard to set from a symbolic name. Just take an int.
+		 */
+		g_value_init( &gvalue, otype );
+		g_value_set_flags( &gvalue, atoi( value ) );
+	}
 	else {
 		g_value_init( &gvalue, G_TYPE_STRING );
 		g_value_set_string( &gvalue, value );
diff --git a/tools/vips.c b/tools/vips.c
index 366374dd..c0074a1c 100644
--- a/tools/vips.c
+++ b/tools/vips.c
@@ -68,8 +68,8 @@
 
 /*
 #define DEBUG
- */
 #define DEBUG_FATAL
+ */
 
 /* Need to disable these sometimes.
 #undef DEBUG_FATAL