--- configure.in	(révision 2054)
+++ configure.in	(copie de travail)
@@ -80,7 +80,7 @@ 
 AC_SUBST(LIBXML_CFLAGS)
 AC_SUBST(LIBXML_LIBS)
 
-PKG_CHECK_MODULES(LIBPNG, "libpng", [have_png_support=yes], [have_png_support=no])
+PKG_CHECK_MODULES(LIBPNG, "libpng zlib", [have_png_support=yes], [have_png_support=no])
 AC_SUBST(LIBPNG_CFLAGS)
 AC_SUBST(LIBPNG_LIBS)
 
--- subrip/subp2pgm.c	(révision 2054)
+++ subrip/subp2pgm.c	(copie de travail)
@@ -44,6 +44,7 @@ 
 
 #ifdef HAVE_PNG_SUPPORT
 #include <png.h>
+#include <zlib.h>
 #endif
 
 #ifdef HAVE_TIFF_SUPPORT