diff --git a/time.go b/time.go
index 7e7a8ea..d995e4e 100644
--- a/time.go
+++ b/time.go
@@ -61,7 +61,7 @@ func CustomDurationString(diff time.Duration, numParts int, glue string) string
 		}
 		if value > 0 {
 			part := fmt.Sprintf("%d %s", value, mag.Name)
-			if value > 1 {
+			if !(value == 1 || value == -1) {
 				part += "s"
 			}
 
diff --git a/time_test.go b/time_test.go
index bb4c0b1..b197fd4 100644
--- a/time_test.go
+++ b/time_test.go
@@ -109,6 +109,10 @@ func TestCustomRelTime(t *testing.T) {
 	t2, _ = time.Parse(timeFormat, "Mon Jan 3 15:00:02.000")
 	testCustomRelTime(t, t1, t2, 3, " ", "4 minutes 3 seconds")
 
+	t1, _ = time.Parse(timeFormat, "Mon Jan 3 15:04:05.000")
+	t2, _ = time.Parse(timeFormat, "Mon Jan 3 15:00:04.000")
+	testCustomRelTime(t, t1, t2, 3, " ", "4 minutes 1 second")
+
 	t1, _ = time.Parse(timeFormat, "Mon Jan 3 15:04:05.000")
 	t2, _ = time.Parse(timeFormat, "Mon Jan 3 15:00:02.001")
 	testCustomRelTime(t, t1, t2, 3, " ", "4 minutes 2 seconds")