diff --git a/src/histogram.js b/src/histogram.js
index 9a31e1dc..8cb7f487 100644
--- a/src/histogram.js
+++ b/src/histogram.js
@@ -30,7 +30,7 @@ export default function() {
     // Convert number of thresholds into uniform thresholds.
     if (!Array.isArray(tz)) {
       tz = tickStep(x0, x1, tz);
-      tz = range(Math.ceil(x0 / tz) * tz, Math.floor(x1 / tz) * tz, tz); // exclusive
+      tz = range(Math.ceil(x0 / tz) * tz, x1, tz); // exclusive
     }
 
     // Remove any thresholds outside the domain.
diff --git a/test/histogram-test.js b/test/histogram-test.js
index c4af048f..c52db3d1 100644
--- a/test/histogram-test.js
+++ b/test/histogram-test.js
@@ -122,6 +122,18 @@ tape("histogram.thresholds(function) sets the bin thresholds accessor", function
   test.end();
 });
 
+tape("histogram()() returns bins whose rightmost bin is not too wide", function(test) {
+  var h = arrays.histogram();
+  test.deepEqual(h([9.8, 10, 11, 12, 13, 13.2]), [
+    bin([9.8], 9.8, 10),
+    bin([10], 10, 11),
+    bin([11], 11, 12),
+    bin([12], 12, 13),
+    bin([13, 13.2], 13, 13.2),
+  ]);
+  test.end();
+});
+
 function bin(bin, x0, x1)  {
   bin.x0 = x0;
   bin.x1 = x1;