diff --git a/include/common/time.h b/include/common/time.h
index 588180d..5d86ad5 100644
--- a/include/common/time.h
+++ b/include/common/time.h
@@ -50,6 +50,7 @@
 #define SETNOW(a)		(*a=now)
 
 extern unsigned int   curr_sec_ms;      /* millisecond of current second (0..999) */
+extern unsigned int   ms_left_scaled;   /* milliseconds left for current second (0..2^32-1) */
 extern unsigned int   curr_sec_ms_scaled;  /* millisecond of current second (0..2^32-1) */
 extern unsigned int   now_ms;           /* internal date in milliseconds (may wrap) */
 extern unsigned int   samp_time;        /* total elapsed time over current sample */
diff --git a/src/freq_ctr.c b/src/freq_ctr.c
index 28f5936..6dec970 100644
--- a/src/freq_ctr.c
+++ b/src/freq_ctr.c
@@ -47,7 +47,7 @@
 	if (past <= 1 && !curr)
 		return past; /* very low rate, avoid flapping */
 
-	return curr + mul32hi(past, ~curr_sec_ms_scaled);
+	return curr + mul32hi(past, ms_left_scaled);
 }
 
 /* returns the number of remaining events that can occur on this freq counter
@@ -59,7 +59,6 @@
 	unsigned int curr, past;
 	unsigned int age;
 
-	past = 0;
 	curr = 0;		
 	age = now.tv_sec - ctr->curr_sec;
 
@@ -69,7 +68,7 @@
 			curr = past;
 			past = ctr->prev_ctr;
 		}
-		curr += mul32hi(past, ~curr_sec_ms_scaled);
+		curr += mul32hi(past, ms_left_scaled);
 	}
 	curr += pend;
 
@@ -99,7 +98,7 @@
 			curr = past;
 			past = ctr->prev_ctr;
 		}
-		curr += mul32hi(past, ~curr_sec_ms_scaled);
+		curr += mul32hi(past, ms_left_scaled);
 	}
 	curr += pend;
 
diff --git a/src/time.c b/src/time.c
index 4149316..6118762 100644
--- a/src/time.c
+++ b/src/time.c
@@ -16,8 +16,8 @@
 #include <common/standard.h>
 #include <common/time.h>
 
-unsigned int   curr_sec_ms;      /* millisecond of current second (0..999) */
-unsigned int   curr_sec_ms_scaled;  /* millisecond of current second (0..2^32-1) */
+unsigned int   curr_sec_ms;     /* millisecond of current second (0..999) */
+unsigned int   ms_left_scaled;  /* milliseconds left for current second (0..2^32-1) */
 unsigned int   now_ms;          /* internal date in milliseconds (may wrap) */
 unsigned int   samp_time;       /* total elapsed time over current sample */
 unsigned int   idle_time;       /* total idle time over current sample */
@@ -203,7 +203,17 @@
  to_ms:
 	now = adjusted;
 	curr_sec_ms = now.tv_usec / 1000;            /* ms of current second */
-	curr_sec_ms_scaled = curr_sec_ms * 4294971;  /* ms * 2^32 / 1000 */
+
+	/* For frequency counters, we'll need to know the ratio of the previous
+	 * value to add to current value depending on the current millisecond.
+	 * The principle is that during the first millisecond, we use 999/1000
+	 * of the past value and that during the last millisecond we use 0/1000
+	 * of the past value. In summary, we only use the past value during the
+	 * first 999 ms of a second, and the last ms is used to complete the
+	 * current measure. The value is scaled to (2^32-1) so that a simple
+	 * multiply followed by a shift gives us the final value.
+	 */
+	ms_left_scaled = (999U - curr_sec_ms) * 4294967U;
 	now_ms = now.tv_sec * 1000 + curr_sec_ms;
 	return;
 }