--- a/src/clean.c
+++ b/src/clean.c
@@ -44,6 +44,7 @@
 
 /*------------------------------- variables ---------------------------------*/
 
+objliststruct *cleanobjlist;
 static LONG		*cleanvictim;
 
 
--- a/src/clean.h
+++ b/src/clean.h
@@ -33,7 +33,7 @@
 
 /*------------------------------- variables ---------------------------------*/
 
-objliststruct	*cleanobjlist;		/* laconic, isn't it? */
+extern objliststruct	*cleanobjlist;		/* laconic, isn't it? */
 
 /*------------------------------- functions ---------------------------------*/
 
--- a/src/extract.c
+++ b/src/extract.c
@@ -40,6 +40,8 @@
 #include	"extract.h"
 #include	"plist.h"
 
+PIXTYPE   *dumscan;
+
 /*------------------------- Static buffers for lutz() -----------------------*/
 
 static infostruct	*info, *store;
--- a/src/extract.h
+++ b/src/extract.h
@@ -37,7 +37,7 @@
 				status;	/* Extraction status */
 
 /*--------------------------------- variables -------------------------------*/
-PIXTYPE		*dumscan;
+extern PIXTYPE		*dumscan;
 
 /*------------------------------- structures --------------------------------*/
 /* Temporary object parameters during extraction */
--- a/src/filter.c
+++ b/src/filter.c
@@ -44,6 +44,8 @@
 #include	"filter.h"
 #include	"image.h"
 
+filterstruct  *thefilter;
+
 /******************************** convolve ***********************************/
 /*
 Convolve a scan line with an array.
--- a/src/filter.h
+++ b/src/filter.h
@@ -43,7 +43,7 @@
   struct structbpann	*bpann;
   }	filterstruct;
 
-filterstruct	*thefilter;
+extern filterstruct	*thefilter;
 
 /*------------------------------- functions ---------------------------------*/
 void		convolve(picstruct *, PIXTYPE *, int y),
--- a/src/fits/fitscat.c
+++ b/src/fits/fitscat.c
@@ -42,6 +42,10 @@
 #include	"fitscat_defs.h"
 #include	"fitscat.h"
 
+float      ctg[37], stg[37];
+char     gstr[MAXCHAR];
+int   bswapflag;
+
 /****** 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
@@ -30,13 +30,13 @@
 
 /*----------------------- miscellaneous variables ---------------------------*/
 
-sexcatstruct		thecat;
-picstruct		thefield1,thefield2, thewfield1,thewfield2;
-objstruct		flagobj;
-obj2struct		flagobj2;
+extern sexcatstruct		thecat;
+extern picstruct		thefield1,thefield2, thewfield1,thewfield2;
+extern objstruct		flagobj;
+extern obj2struct		flagobj2;
 extern obj2struct	outobj2;
-float			ctg[37], stg[37];
-char			gstr[MAXCHAR];
+extern float			ctg[37], stg[37];
+extern char			gstr[MAXCHAR];
 
 /*------------------------------- functions ---------------------------------*/
 extern void	alloccatparams(void),
--- a/src/plist.c
+++ b/src/plist.c
@@ -38,6 +38,11 @@
 #include	"prefs.h"
 #include	"plist.h"
 
+int plistexist_value, plistexist_dvalue, plistexist_cdvalue,
+  plistexist_flag, plistexist_wflag, plistexist_dthresh, plistexist_var,
+  plistoff_value, plistoff_dvalue, plistoff_cdvalue,
+  plistoff_flag[MAXFLAG], plistoff_wflag, plistoff_dthresh, plistoff_var,
+  plistsize;
 
 /******************************** createblank *******************************
 PROTO   int createblank(int no, objliststruct *objlist)
--- a/src/plist.h
+++ b/src/plist.h
@@ -47,7 +47,7 @@
 
 /*-------------------------------- globals ----------------------------------*/
 
-int	plistexist_value, plistexist_dvalue, plistexist_cdvalue,
+extern int	plistexist_value, plistexist_dvalue, plistexist_cdvalue,
 	plistexist_flag, plistexist_wflag, plistexist_dthresh, plistexist_var,
 	plistoff_value, plistoff_dvalue, plistoff_cdvalue,
 	plistoff_flag[MAXFLAG], plistoff_wflag, plistoff_dthresh, plistoff_var,
--- a/src/preflist.h
+++ b/src/preflist.h
@@ -39,7 +39,7 @@
 #endif
 
 /*-------------------------------- initialization ---------------------------*/
- int	idummy;
+extern int	idummy;
 
  pkeystruct key[] =
  {
--- a/src/prefs.c
+++ b/src/prefs.c
@@ -56,6 +56,9 @@
 #include	"preflist.h"
 #include	"fits/fitscat.h"
 
+prefstruct    prefs;
+double  ddummy;
+int idummy;
 
 /********************************* dumpprefs ********************************/
 /*
--- a/src/prefs.h
+++ b/src/prefs.h
@@ -249,7 +249,7 @@
   int		nthreads;			/* Number of active threads */
   }	prefstruct;
 
-  prefstruct		prefs;
+extern  prefstruct		prefs;
 
 /*-------------------------------- protos -----------------------------------*/
 extern int	cistrcmp(char *cs, char *ct, int mode);
--- a/src/psf.c
+++ b/src/psf.c
@@ -47,6 +47,9 @@
 
 /*------------------------------- variables ---------------------------------*/
 
+psfstruct *psf,*thedpsf,*thepsf;
+psfitstruct *thepsfit,*thedpsfit;
+PIXTYPE   *checkmask;
 
 extern keystruct	objkey[];
 extern objstruct	outobj;
--- a/src/psf.h
+++ b/src/psf.h
@@ -102,9 +102,9 @@
   }	psfitstruct;
 
 /*----------------------------- Global variables ----------------------------*/
-psfstruct	*psf,*thedpsf,*thepsf;
-psfitstruct	*thepsfit,*thedpsfit;
-PIXTYPE		*checkmask;
+extern psfstruct	*psf,*thedpsf,*thepsf;
+extern psfitstruct	*thepsfit,*thedpsfit;
+extern PIXTYPE		*checkmask;
 
 /*-------------------------------- functions --------------------------------*/
 extern void	compute_pos(int *pnpsf,int *pconvflag,int *pnpsfflag,
--- a/src/retina.c
+++ b/src/retina.c
@@ -42,6 +42,7 @@
 #include	"image.h"
 #include	"retina.h"
 
+retistruct  *theretina;
 
 /******************************** readretina *********************************/
 /*
--- a/src/retina.h
+++ b/src/retina.h
@@ -38,7 +38,7 @@
   struct structbpann	*bpann;	/* The neural network */
   }     retistruct;
 
-retistruct	*theretina;
+extern retistruct	*theretina;
 
 /*------------------------------- functions ---------------------------------*/
 
--- a/src/sexhead1.h
+++ b/src/sexhead1.h
@@ -26,8 +26,8 @@
 *
 *%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 
-int	idummy;
-double	ddummy;
+extern int	idummy;
+extern double	ddummy;
 
 keystruct	headkey1[] = {
   {"EPOCH   ", "",
--- a/src/som.c
+++ b/src/som.c
@@ -41,6 +41,8 @@
 #include	"prefs.h"
 #include	"som.h"
 
+somstruct *thesom;
+
 /********************************* som_phot **********************************/
 /*
 Perform SOM-fitting on a detected source: returns node number of the
--- a/src/som.h
+++ b/src/som.h
@@ -70,7 +70,7 @@
   float		stderror;		/* Global reduced error */
   }	somstruct;
 
-somstruct	*thesom;
+extern somstruct	*thesom;
 
 /*---------------------------------- protos --------------------------------*/
 
--- a/src/xml.c
+++ b/src/xml.c
@@ -50,6 +50,11 @@
 xmlstruct		*xmlstack = NULL;
 int			nxml=0, nxmlmax=0;
 
+sexcatstruct    thecat;
+picstruct   thefield1,thefield2, thewfield1,thewfield2;
+objstruct   flagobj;
+obj2struct    flagobj2;
+
 /****** init_xml ************************************************************
 PROTO	int	init_xml(void)
 PURPOSE	Initialize a set of meta-data kept in memory before being written to the