diff --git a/tc/tc_core.c b/tc/tc_core.c
index 8c3a2ac..1365e08 100644
--- a/tc/tc_core.c
+++ b/tc/tc_core.c
@@ -26,7 +26,7 @@
 static double tick_in_usec = 1;
 static double clock_factor = 1;
 
-int tc_core_time2big(long time)
+int tc_core_time2big(unsigned time)
 {
 	__u64 t = time;
 
diff --git a/tc/tc_core.h b/tc/tc_core.h
index b1ede1e..3a0ed7c 100644
--- a/tc/tc_core.h
+++ b/tc/tc_core.h
@@ -6,7 +6,7 @@
 
 #define TIME_UNITS_PER_SEC	1000000
 
-int  tc_core_time2big(long time);
+int  tc_core_time2big(unsigned time);
 unsigned tc_core_time2tick(unsigned time);
 unsigned tc_core_tick2time(unsigned tick);
 unsigned tc_core_time2ktime(unsigned time);