1 files changed, 3 insertions, 0 deletions
diff --git a/lib/pnm.h b/lib/pnm.h
index a8aad161..fd262566 100644
--- a/lib/pnm.h
+++ b/lib/pnm.h
@@ -136,6 +136,9 @@ pnm_invertxel(xel *  const x,
               xelval const maxval,
               int    const format);
 
+const char *
+pnm_formattypenm(int const format);
+
 void
 pnm_promoteformat(xel** xels, int cols, int rows, xelval maxval, int format,
                   xelval newmaxval, int newformat);