diff --git a/lrsnashlib.c b/lrsnashlib.c
index a9f3ff5..03052a8 100644
--- a/lrsnashlib.c
+++ b/lrsnashlib.c
@@ -1118,4 +1118,7 @@ void updateFwidth(game *g, int col, int pos, char *str) {
                 ((gInfo *)g->aux)->fwidth[col][pos] = len;
 }
 
+// Definition of extern variable declared in the .h
+long FirstTime;
+
 /******************** end of lrsnashlib.c ***************************/
diff --git a/lrsnashlib.h b/lrsnashlib.h
index 893a5f9..e8a4c12 100644
--- a/lrsnashlib.h
+++ b/lrsnashlib.h
@@ -67,7 +67,7 @@ void initFwidth(game *g);
 void updateFwidth(game *g, int col, int pos, char *str);
 
 
-long FirstTime;          /* set this to true for every new game to be solved */
+extern long FirstTime;   /* set this to true for every new game to be solved */
 static long Debug_flag;
 static long Verbose_flag;