1 files changed, 6 insertions, 0 deletions
diff --git a/converter/other/pngtopnm.c b/converter/other/pngtopnm.c
index c21420a7..0ee08ede 100644
--- a/converter/other/pngtopnm.c
+++ b/converter/other/pngtopnm.c
@@ -44,6 +44,12 @@
 #include "nstring.h"
 #include "shhopt.h"
 
+#if PNG_LIBPNG_VER >= 10400
+#error Your PNG library (<png.h>) is incompatible with this Netpbm source code.
+#error You need either an older PNG library (older than 1.4)
+#error newer Netpbm source code (at least 10.48)
+#endif
+
 typedef struct _jmpbuf_wrapper {
   jmp_buf jmpbuf;
 } jmpbuf_wrapper;