diff --git a/doc/gtk-doc.make b/doc/gtk-doc.make
index e7916563..9ccd0b04 100644
--- a/doc/gtk-doc.make
+++ b/doc/gtk-doc.make
@@ -25,6 +25,7 @@ TARGET_DIR=$(HTML_DIR)/$(DOC_MODULE)
 
 SETUP_FILES = \
 	$(content_files)		\
+	$(expand_content_files)		\
 	$(DOC_MAIN_SGML_FILE)		\
 	$(DOC_MODULE)-sections.txt	\
 	$(DOC_MODULE)-overrides.txt
@@ -86,7 +87,7 @@ GTK_DOC_V_SETUP_0=@echo "  DOC   Preparing build";
 
 setup-build.stamp:
 	-$(GTK_DOC_V_SETUP)if test "$(abs_srcdir)" != "$(abs_builddir)" ; then \
-	    files=`echo $(SETUP_FILES) $(expand_content_files) $(DOC_MODULE).types`; \
+	    files=`echo $(SETUP_FILES) $(DOC_MODULE).types`; \
 	    if test "x$$files" != "x" ; then \
 	        for file in $$files ; do \
 	            destdir=`dirname $(abs_builddir)/$$file`; \
@@ -118,7 +119,7 @@ scan-build.stamp: setup-build.stamp $(HFILE_GLOB) $(CFILE_GLOB)
 	$(GTK_DOC_V_INTROSPECT)if grep -l '^..*$$' $(DOC_MODULE).types > /dev/null 2>&1 ; then \
 	    scanobj_options=""; \
 	    gtkdoc-scangobj 2>&1 --help | grep  >/dev/null "\-\-verbose"; \
-	    if test "$(?)" = "0"; then \
+	    if test "$$?" = "0"; then \
 	        if test "x$(V)" = "x1"; then \
 	            scanobj_options="--verbose"; \
 	        fi; \
@@ -162,17 +163,17 @@ GTK_DOC_V_XREF=$(GTK_DOC_V_XREF_$(V))
 GTK_DOC_V_XREF_=$(GTK_DOC_V_XREF_$(AM_DEFAULT_VERBOSITY))
 GTK_DOC_V_XREF_0=@echo "  DOC   Fixing cross-references";
 
-html-build.stamp: sgml.stamp $(DOC_MAIN_SGML_FILE) $(content_files)
+html-build.stamp: sgml.stamp $(DOC_MAIN_SGML_FILE) $(content_files) $(expand_content_files)
 	$(GTK_DOC_V_HTML)rm -rf html && mkdir html && \
 	mkhtml_options=""; \
 	gtkdoc-mkhtml 2>&1 --help | grep  >/dev/null "\-\-verbose"; \
-	if test "$(?)" = "0"; then \
+	if test "$$?" = "0"; then \
 	  if test "x$(V)" = "x1"; then \
 	    mkhtml_options="$$mkhtml_options --verbose"; \
 	  fi; \
 	fi; \
 	gtkdoc-mkhtml 2>&1 --help | grep  >/dev/null "\-\-path"; \
-	if test "$(?)" = "0"; then \
+	if test "$$?" = "0"; then \
 	  mkhtml_options="$$mkhtml_options --path=\"$(abs_srcdir)\""; \
 	fi; \
 	cd html && gtkdoc-mkhtml $$mkhtml_options $(MKHTML_OPTIONS) $(DOC_MODULE) ../$(DOC_MAIN_SGML_FILE)
@@ -194,11 +195,11 @@ GTK_DOC_V_PDF=$(GTK_DOC_V_PDF_$(V))
 GTK_DOC_V_PDF_=$(GTK_DOC_V_PDF_$(AM_DEFAULT_VERBOSITY))
 GTK_DOC_V_PDF_0=@echo "  DOC   Building PDF";
 
-pdf-build.stamp: sgml.stamp $(DOC_MAIN_SGML_FILE) $(content_files)
+pdf-build.stamp: sgml.stamp $(DOC_MAIN_SGML_FILE) $(content_files) $(expand_content_files)
 	$(GTK_DOC_V_PDF)rm -f $(DOC_MODULE).pdf && \
 	mkpdf_options=""; \
 	gtkdoc-mkpdf 2>&1 --help | grep  >/dev/null "\-\-verbose"; \
-	if test "$(?)" = "0"; then \
+	if test "$$?" = "0"; then \
 	  if test "x$(V)" = "x1"; then \
 	    mkpdf_options="$$mkpdf_options --verbose"; \
 	  fi; \
@@ -223,12 +224,15 @@ clean-local:
 	@if echo $(SCAN_OPTIONS) | grep -q "\-\-rebuild-types" ; then \
 	  rm -f $(DOC_MODULE).types; \
 	fi
+	@if echo $(SCAN_OPTIONS) | grep -q "\-\-rebuild-sections" ; then \
+	  rm -f $(DOC_MODULE)-sections.txt; \
+	fi
 
 distclean-local:
 	@rm -rf xml html $(REPORT_FILES) $(DOC_MODULE).pdf \
 	    $(DOC_MODULE)-decl-list.txt $(DOC_MODULE)-decl.txt
 	@if test "$(abs_srcdir)" != "$(abs_builddir)" ; then \
-	    rm -f $(SETUP_FILES) $(expand_content_files) $(DOC_MODULE).types; \
+	    rm -f $(SETUP_FILES) $(DOC_MODULE).types; \
 	fi
 
 maintainer-clean-local:
diff --git a/libvips/foreign/dzsave.c b/libvips/foreign/dzsave.c
index cee9bda7..aabde107 100644
--- a/libvips/foreign/dzsave.c
+++ b/libvips/foreign/dzsave.c
@@ -454,6 +454,12 @@ struct _VipsForeignSaveDz {
 	 * Track bytes written here and try to guess when we'll go over.
 	 */
 	size_t bytes_written;
+
+	/* save->background turned into a pixel that matches the image we are
+	 * saving .. used to test for blank tiles.
+	 */
+	VipsPel *ink;
+
 };
 
 typedef VipsForeignSaveClass VipsForeignSaveDzClass;
@@ -1074,6 +1080,47 @@ tile_name( Layer *layer, int x, int y )
 	return( out );
 }
 
+static gboolean
+tile_equal( VipsImage *image, VipsPel * restrict ink )
+{
+	const int bytes = VIPS_IMAGE_SIZEOF_PEL( image );
+
+	VipsRect rect;
+	VipsRegion *region;
+	int x, y, b;
+
+	region = vips_region_new( image ); 
+
+	/* We know @image is part of a memory buffer, so this will be quick.
+	 */
+	rect.left = 0;
+	rect.top = 0;
+	rect.width = image->Xsize;
+	rect.height = image->Ysize;
+	if( vips_region_prepare( region, &rect ) ) {
+		g_object_unref( region );
+		return( FALSE ); 
+	}
+
+	for( y = 0; y < image->Ysize; y++ ) {
+		VipsPel * restrict p = VIPS_REGION_ADDR( region, 0, y ); 
+
+		for( x = 0; x < image->Xsize; x++ ) {
+			for( b = 0; b < bytes; b++ ) 
+				if( p[b] != ink[b] ) {
+					g_object_unref( region );
+					return( FALSE ); 
+				}
+
+			p += bytes;
+		}
+	}
+
+	g_object_unref( region );
+
+	return( TRUE );
+}
+
 static int
 strip_work( VipsThreadState *state, void *a )
 {
@@ -1094,7 +1141,7 @@ strip_work( VipsThreadState *state, void *a )
 	printf( "strip_work\n" );
 #endif /*DEBUG_VERBOSE*/
 
-	/* If we are centring we may be outside the real pixels. Skip in 
+	/* If we are centering we may be outside the real pixels. Skip in 
 	 * this case, and the viewer will display blank.png for us. 
 	 */
 	if( dz->centre ) {
@@ -1127,6 +1174,20 @@ strip_work( VipsThreadState *state, void *a )
 		state->pos.width, state->pos.height, NULL ) ) 
 		return( -1 );
 
+	/* If we are writing a google map pyramid and the tile is equal to the 
+	 * background, don't save. The viewer will display blank.png for us.
+	 */
+	if( dz->layout == VIPS_FOREIGN_DZ_LAYOUT_GOOGLE &&
+		tile_equal( x, dz->ink ) ) { 
+#ifdef DEBUG_VERBOSE
+		printf( "strip_work: skipping blank tile %d x %d\n", 
+			state->x / dz->tile_size, 
+			state->y / dz->tile_size ); 
+#endif /*DEBUG_VERBOSE*/
+
+		return( 0 ); 
+	}
+
 	/* Google tiles need to be padded up to tilesize.
 	 */
 	if( dz->layout == VIPS_FOREIGN_DZ_LAYOUT_GOOGLE ) {
@@ -1528,6 +1589,16 @@ vips_foreign_save_dz_build( VipsObject *object )
 		vips_area_unref( VIPS_AREA( background ) ); 
 	}
 
+	/* We use ink in google mode to check for blank tiles.
+	 */
+	if( dz->layout == VIPS_FOREIGN_DZ_LAYOUT_GOOGLE ) {
+		if( !(dz->ink = vips__vector_to_ink( 
+			class->nickname, save->ready,
+			VIPS_AREA( save->background )->data, NULL, 
+			VIPS_AREA( save->background )->n )) )
+			return( -1 );
+	}
+
 	if( dz->overlap >= dz->tile_size ) {
 		vips_error( "dzsave", 
 			"%s", _( "overlap must be less than tile "