diff -ruN gwyddion-2.47.orig/configure.ac gwyddion-2.47/configure.ac
--- gwyddion-2.47.orig/configure.ac	2016-11-18 11:17:57.000000000 +0100
+++ gwyddion-2.47/configure.ac	2020-01-24 04:39:18.892183563 +0100
@@ -632,11 +632,13 @@
 #############################################################################
 # CFITSIO
 # Optional.  Used for FITS image import.
-enable_cfitsio=yes
-PKG_CHECK_MODULES(CFITSIO, [cfitsio],
+GWY_WITH([cfitsio],,[build with cfitsio support])
+if test "x$enable_cfitsio" != "xno"; then
+  PKG_CHECK_MODULES(CFITSIO, [cfitsio],
                   [AC_DEFINE(HAVE_CFITSIO,1,
                             [Define if we have the cfitsio package.])],
                   [enable_cfitsio=no])
+fi
 AM_CONDITIONAL([HAVE_CFITSIO],[test x$enable_cfitsio != xno])
 
 #############################################################################