2 files changed, 3 insertions, 3 deletions
diff --git a/xpr.c b/xpr.c
index cdc2143..0e75400 100644
--- a/xpr.c
+++ b/xpr.c
@@ -131,8 +131,8 @@ int debug = 0;
 
 #define DEFAULT_CUTOFF ((unsigned int) (0xFFFF * 0.50))
 
-static char *infilename = NULL;
-char *progname   = NULL;
+static const char *infilename = NULL;
+const char *progname   = NULL;
 
 typedef struct _grayRec {
     int level;
diff --git a/xpr.h b/xpr.h
index d7c3182..a7d09c1 100644
--- a/xpr.h
+++ b/xpr.h
@@ -32,7 +32,7 @@ enum orientation {
 enum device {LN01, LN03, LA100, PS, PP, LJET, PJET, PJETXL};
 
 /* Global variables */
-extern char *progname;
+extern const char *progname;
 extern int debug;
 
 /* Global prototypes */