diff --git a/doc/Makefile.am b/doc/Makefile.am
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -14,21 +14,24 @@
 	doc/CMakeLists.txt
 
 DOC_EPS_IMAGES18 = \
+	grid_graph.eps \
+	nodeshape_0.eps \
+	nodeshape_1.eps \
+	nodeshape_2.eps \
+	nodeshape_3.eps \
+	nodeshape_4.eps
+
+DOC_EPS_IMAGES27 = \
 	bipartite_matching.eps \
 	bipartite_partitions.eps \
 	connected_components.eps \
 	edge_biconnected_components.eps \
-	grid_graph.eps \
 	node_biconnected_components.eps \
-	nodeshape_0.eps \
-	nodeshape_1.eps \
-	nodeshape_2.eps \
-	nodeshape_3.eps \
-	nodeshape_4.eps \
 	strongly_connected_components.eps
 
 DOC_EPS_IMAGES = \
-	$(DOC_EPS_IMAGES18)
+	$(DOC_EPS_IMAGES18) \
+	$(DOC_EPS_IMAGES27)
 
 DOC_PNG_IMAGES = \
 	$(DOC_EPS_IMAGES:%.eps=doc/gen-images/%.png)
@@ -51,6 +54,17 @@
 	  exit 1; \
 	fi
 
+$(DOC_EPS_IMAGES27:%.eps=doc/gen-images/%.png): doc/gen-images/%.png: doc/images/%.eps
+	-mkdir doc/gen-images
+	if test ${gs_found} = yes; then \
+	  $(GS_COMMAND) -sDEVICE=pngalpha -r27 -sOutputFile=$@ $<; \
+	else \
+	  echo; \
+	  echo "Ghostscript not found."; \
+	  echo; \
+	  exit 1; \
+	fi
+
 html-local: $(DOC_PNG_IMAGES)
 	if test ${doxygen_found} = yes; then \
 	  cd doc; \