diff --git a/libvips/histogram/maplut.c b/libvips/histogram/maplut.c
index 63f1b848..f4ee5c31 100644
--- a/libvips/histogram/maplut.c
+++ b/libvips/histogram/maplut.c
@@ -71,8 +71,6 @@
 
 #include <vips/vips.h>
 
-#include "phistogram.h"
-
 typedef struct _VipsMaplut {
 	VipsOperation parent_instance;
 
@@ -618,13 +616,13 @@ vips_maplut_class_init( VipsMaplutClass *class )
 		_( "Input" ), 
 		_( "Input image" ),
 		VIPS_ARGUMENT_REQUIRED_INPUT, 
-		G_STRUCT_OFFSET( VipsHistogram, in ) );
+		G_STRUCT_OFFSET( VipsMaplut, in ) );
 
 	VIPS_ARG_IMAGE( class, "out", 1, 
 		_( "Output" ), 
 		_( "Output image" ),
 		VIPS_ARGUMENT_REQUIRED_OUTPUT, 
-		G_STRUCT_OFFSET( VipsHistogram, out ) );
+		G_STRUCT_OFFSET( VipsMaplut, out ) );
 
 	VIPS_ARG_IMAGE( class, "lut", 2, 
 		_( "LUT" ),