--- a/src/fits/fitscat.c
+++ b/src/fits/fitscat.c
@@ -42,6 +42,9 @@
 #include	"fitscat_defs.h"
 #include	"fitscat.h"
 
+int   bswapflag;
+char    gstr[MAXCHAR];
+
 /****** about_cat **************************************************************
 PROTO	int about_cat(catstruct *cat, FILE *stream)
 PURPOSE	Print some info about a catalog.
--- a/src/fits/fitscat_defs.h
+++ b/src/fits/fitscat_defs.h
@@ -86,7 +86,7 @@
 typedef	int		LONG;			/* for DEC-Alpha... */
 	
 /*----------------------------- Internal constants --------------------------*/
-char		gstr[MAXCHAR];
+extern char		gstr[MAXCHAR];
 
 /*----------------------------- External constants --------------------------*/
 
--- a/src/fits/fitscat.h
+++ b/src/fits/fitscat.h
@@ -333,6 +333,6 @@
 		warning(char *msg1, char *msg2);
 
 
-int		bswapflag;
+extern int		bswapflag;
 
 #endif
--- a/src/globals.h
+++ b/src/globals.h
@@ -29,7 +29,7 @@
 #include "types.h"
 
 /*----------------------- miscellaneous variables ---------------------------*/
-char		gstr[MAXCHAR];
+extern char		gstr[MAXCHAR];
 
 /*------------------------------- functions ---------------------------------*/
 extern void	makeit(void);
--- a/src/prefs.c
+++ b/src/prefs.c
@@ -59,6 +59,8 @@
 #include "prefs.h"
 #include "preflist.h"
 
+prefstruct  prefs;
+
 /********************************* dumpprefs ********************************/
 /*
 Print the default preference parameters.
--- a/src/prefs.h
+++ b/src/prefs.h
@@ -149,7 +149,7 @@
   int		nobj;				/* Number of sources added */
         }	prefstruct;
 
-prefstruct	prefs;
+extern prefstruct	prefs;
 
 /*-------------------------------- protos -----------------------------------*/
 extern int	cistrcmp(char *cs, char *ct, int mode);