diff --git imagemagick-clean/MagickCore/fx.c imagemagick-workdir/MagickCore/fx.c
index dc96e9bd..3b4cda5e 100644
--- imagemagick-clean/MagickCore/fx.c
+++ imagemagick-workdir/MagickCore/fx.c
@@ -38,6 +38,8 @@
 %
 */
 
+double j0(double x);
+double j1(double x);
 /*
   Include declarations.
 */