diff --git a/src/histogram.rs b/src/histogram.rs
index 293415a..f51459e 100644
--- a/src/histogram.rs
+++ b/src/histogram.rs
@@ -34,7 +34,7 @@ macro_rules! define_histogram {
                 let step = (end - start) / (LEN as f64);
                 let mut range = [0.; LEN + 1];
                 for (i, r) in range.iter_mut().enumerate() {
-                    *r = step * (i as f64);
+                    *r = start + step * (i as f64);
                 }
 
                 Self {
diff --git a/tests/histogram.rs b/tests/histogram.rs
index 86d2c5a..24b8cf0 100644
--- a/tests/histogram.rs
+++ b/tests/histogram.rs
@@ -10,8 +10,8 @@ define_histogram!(Histogram10, 10);
 
 #[test]
 fn with_const_width() {
-    let mut h = Histogram10::with_const_width(0., 100.);
-    for i in 0..100 {
+    let mut h = Histogram10::with_const_width(-30., 70.);
+    for i in -30..70 {
         h.add(f64::from(i)).unwrap();
     }
     assert_eq!(h.bins(), &[10, 10, 10, 10, 10, 10, 10, 10, 10, 10]);