--- a/ui_common.c
+++ b/ui_common.c
@@ -28,6 +28,13 @@
 extern int history_pos;
 extern int history_len;
 
+sorted_list_type screen_list;
+host_pair_line totals;
+int peaksent, peakrecv, peaktotal;
+history_type history_totals;
+hash_type* screen_hash;
+hash_type* service_hash;
+
 /*
  * Compare two screen lines based on bandwidth.  Start comparing from the 
  * specified column
--- a/ui_common.h
+++ b/ui_common.h
@@ -33,12 +33,12 @@
 
 extern options_t options;
 
-sorted_list_type screen_list;
-host_pair_line totals;
-int peaksent, peakrecv, peaktotal;
+extern sorted_list_type screen_list;
+extern host_pair_line totals;
+extern int peaksent, peakrecv, peaktotal;
 extern history_type history_totals;
-hash_type* screen_hash;
-hash_type* service_hash;
+extern hash_type* screen_hash;
+extern hash_type* service_hash;
 
 void analyse_data(void);
 void screen_list_init(void);
--- a/ui.c
+++ b/ui.c
@@ -253,7 +253,6 @@
     }
 }
 
-extern history_type history_totals;
 
 
 void ui_print() {
--- a/iftop.c
+++ b/iftop.c
@@ -66,7 +66,6 @@
 extern options_t options;
 
 hash_type* history;
-history_type history_totals;
 time_t last_timestamp;
 time_t first_timestamp;
 int history_pos = 0;