--- a/src/DLD-FUNCTIONS/colamd.cc
+++ b/src/DLD-FUNCTIONS/colamd.cc
@@ -39,6 +39,8 @@
 #include "ov-re-sparse.h"
 #include "ov-cx-sparse.h"
 
+#if SIZEOF_INT == SIZEOF_OCTAVE_IDX_TYPE
+
 // External COLAMD functions in C
 extern "C" {
 #include "COLAMD/colamd.h"
@@ -188,6 +190,8 @@
     }
 }
 
+#endif
+
 DEFUN_DLD (colamd, args, nargout,
     "-*- texinfo -*-\n\
 @deftypefn {Loadable Function} {@var{p} =} colamd (@var{s})\n\
@@ -256,6 +260,9 @@
 @seealso{colperm, symamd}")
 {
   octave_value_list retval;
+
+#if SIZEOF_INT == SIZEOF_OCTAVE_IDX_TYPE
+
   int nargin = args.length ();
   int spumoni = 0;
  
@@ -393,6 +400,12 @@
 	}
     }
 
+#else
+
+  error ("colamd: not available in this version of Octave");
+
+#endif
+
   return retval;
 }
 
@@ -461,6 +474,9 @@
 @seealso{colperm, colamd}")
 {
   octave_value_list retval;
+
+#if SIZEOF_INT == SIZEOF_OCTAVE_IDX_TYPE
+
   int nargin = args.length ();
   int spumoni = 0;
  
@@ -580,6 +596,12 @@
 	}
     }
 
+#else
+
+  error ("symamd: not available in this version of Octave");
+
+#endif
+
   return retval;
 }
 
@@ -600,6 +622,9 @@
 @end deftypefn")
 {
   octave_value_list retval;
+
+#if SIZEOF_INT == SIZEOF_OCTAVE_IDX_TYPE
+
   int nargin = args.length ();
 
   if (nargout < 0 || nargout > 2 || nargin < 0 || nargin > 2)
@@ -705,6 +730,12 @@
 	}
     }
 
+#else
+
+  error ("etree: not available in this version of Octave");
+
+#endif
+
   return retval;
 }