--- a/backend.h
+++ b/backend.h
@@ -242,7 +242,7 @@ extern GameInfo gameInfo;
 
 /* ICS vars used with backend.c and zippy.c */
 enum ICS_TYPE { ICS_GENERIC, ICS_ICC, ICS_FICS, ICS_CHESSNET /* not really supported */ };
-enum ICS_TYPE ics_type;
+extern enum ICS_TYPE ics_type;
 
 /* pgntags.c prototypes
  */
--- a/evalgraph.h
+++ b/evalgraph.h
@@ -34,7 +34,7 @@ typedef enum { PEN_NONE, PEN_BLACK, PEN_DOTTED, PEN_BLUEDOTTED, PEN_BOLDWHITE, P
 #define OPEN   0
 
 /* Module globals */
-ChessProgramStats_Move * currPvInfo;
+extern ChessProgramStats_Move * currPvInfo;
 extern int currFirst;
 extern int currLast;
 extern int currCurrent;
--- a/xaw/xhistory.c
+++ b/xaw/xhistory.c
@@ -96,7 +96,6 @@ ScrollToCursor (Option *opt, int caretPos)
 
 // ------------------------------ callbacks --------------------------
 
-char *historyText;
 char historyTranslations[] =
 "<Btn3Down>: select-start() \n \
 <Btn3Up>: extend-end(PRIMARY) SelectMove() \n";