diff --git a/Makefile b/Makefile
index ac7ae08..3b875b3 100644
--- a/Makefile
+++ b/Makefile
@@ -7,7 +7,7 @@ DOC = cpdfunicodedata cpdferror cpdfdebug cpdfjson cpdfstrftime cpdfcoord \
       cpdfembed cpdfaddtext cpdfimage cpdffont cpdftype cpdfpad cpdfocg \
       cpdfsqueeze cpdfdraft cpdfspot cpdfpagelabels cpdfcreate cpdfannot \
       cpdfxobject cpdfimpose cpdftweak cpdftexttopdf cpdftoc cpdfjpeg \
-      cpdfdraw cpdfcommand
+      cpdfpng cpdfdraw cpdfcommand
 
 MODS = $(NONDOC) $(DOC)
 
@@ -41,7 +41,7 @@ clean ::
 	*.json test/*.pdf debug/*.pdf *.ps *.aux *.idx *.log *.out *.toc *.cut \
 	*.ttf *.ttx
 
-DOC_FILES = $(foreach x,$(DOC),$(x).mli )
+DOC_FILES = $(foreach x,$(DOC),$(x).mli)
 
 install : libinstall
 
diff --git a/cpdfpng.ml b/cpdfpng.ml
new file mode 100644
index 0000000..aaff88d
--- /dev/null
+++ b/cpdfpng.ml
@@ -0,0 +1 @@
+(* PNG *)
diff --git a/cpdfpng.mli b/cpdfpng.mli
new file mode 100644
index 0000000..aaff88d
--- /dev/null
+++ b/cpdfpng.mli
@@ -0,0 +1 @@
+(* PNG *)