diff --git a/packages/turf-isolines/index.ts b/packages/turf-isolines/index.ts
index 077701467d..6ed03bfd02 100644
--- a/packages/turf-isolines/index.ts
+++ b/packages/turf-isolines/index.ts
@@ -104,7 +104,7 @@ function createIsoLines(
   breaksProperties: GeoJsonProperties[]
 ): Feature<MultiLineString>[] {
   const results = [];
-  for (let i = 1; i < breaks.length; i++) {
+  for (let i = 0; i < breaks.length; i++) {
     const threshold = +breaks[i]; // make sure it's a number
 
     const properties = { ...commonProperties, ...breaksProperties[i] };
diff --git a/packages/turf-isolines/test.js b/packages/turf-isolines/test.js
index d0d545271f..5f9bf4658e 100644
--- a/packages/turf-isolines/test.js
+++ b/packages/turf-isolines/test.js
@@ -55,6 +55,39 @@ test("isolines", (t) => {
   t.end();
 });
 
+test("isolines - skipping first break, from issue #2129", (t) => {
+  const points = pointGrid([0, 10, 20, 30], 100);
+  for (var i = 0; i < points.features.length; i++) {
+    points.features[i].properties.temperature = Math.random() * 12;
+  }
+
+  const breaks = [5, 10];
+
+  const lines = isolines(points, breaks, {
+    zProperty: "temperature",
+    breaksProperties: [
+      { name: "break5", stroke: "#F00" },
+      { name: "break10", stroke: "#0F0" },
+    ],
+  });
+
+  lines.features.push(
+    lineString(getCoords(envelope(points))[0], {
+      description: "Debug line for testing",
+      stroke: "#F00",
+      "stroke-width": 1,
+    })
+  );
+
+  // Make sure an isoline is created for each break, and that it's
+  // geometry isn't empty.
+  t.equal(lines.features[0].properties.name, "break5");
+  t.assert(lines.features[0].geometry.coordinates[0].length > 1);
+  t.equal(lines.features[1].properties.name, "break10");
+  t.assert(lines.features[1].geometry.coordinates[0].length > 1);
+  t.end();
+});
+
 test("isolines -- throws", (t) => {
   const points = pointGrid([-70.823364, -33.553984, -70.473175, -33.302986], 5);
 
@@ -92,7 +125,7 @@ test("isolines -- handling properties", (t) => {
     commonProperties: commonProperties,
     breaksProperties: breaksProperties,
   });
-  t.equal(lines.features[0].properties.name, "break2");
+  t.equal(lines.features[0].properties.name, "break1");
   t.equal(lines.features[0].properties.source, "foobar");
   t.end();
 });
diff --git a/packages/turf-isolines/test/in/bigMatrix.json b/packages/turf-isolines/test/in/bigMatrix.json
index a526167eb4..6638fae307 100644
--- a/packages/turf-isolines/test/in/bigMatrix.json
+++ b/packages/turf-isolines/test/in/bigMatrix.json
@@ -1,7 +1,7 @@
 {
   "origin": [6.5, 46],
   "cellSize": 10,
-  "breaks": [0, 0.24, 0.5, 1.5, 2.5, 100],
+  "breaks": [0.24, 0.5, 1.5, 2.5, 100],
   "zProperty": "pressure",
   "commonProperties": {
     "stroke-width": 4,
diff --git a/packages/turf-isolines/test/in/matrix2.json b/packages/turf-isolines/test/in/matrix2.json
index 937a5a0175..491a446c38 100644
--- a/packages/turf-isolines/test/in/matrix2.json
+++ b/packages/turf-isolines/test/in/matrix2.json
@@ -12,7 +12,7 @@
   ],
   "origin": [10.85, 44],
   "cellSize": 20,
-  "breaks": [0, 4.5, 9, 13.5, 18],
+  "breaks": [4.5, 9, 13.5, 18],
   "commonProperties": {
     "stroke-width": 3,
     "stroke": "darkred",
diff --git a/packages/turf-isolines/test/in/pointGrid.geojson b/packages/turf-isolines/test/in/pointGrid.geojson
index 654238762b..f5536d41ce 100644
--- a/packages/turf-isolines/test/in/pointGrid.geojson
+++ b/packages/turf-isolines/test/in/pointGrid.geojson
@@ -1,7 +1,7 @@
 {
   "type": "FeatureCollection",
   "properties": {
-    "breaks": [0, 20, 40, 80, 160],
+    "breaks": [20, 40, 80, 160],
     "breaksProperties": [
       {
         "fill-opacity": 0.5
diff --git a/packages/turf-isolines/test/out/bigMatrix.geojson b/packages/turf-isolines/test/out/bigMatrix.geojson
index bd5e9245ec..529690781b 100644
--- a/packages/turf-isolines/test/out/bigMatrix.geojson
+++ b/packages/turf-isolines/test/out/bigMatrix.geojson
@@ -6,8 +6,8 @@
       "properties": {
         "stroke-width": 4,
         "fill-opacity": 0.4,
-        "stroke": "blue",
-        "fill": "blue",
+        "stroke": "grey",
+        "fill": "grey",
         "pressure": 0.24
       },
       "geometry": {
@@ -265,8 +265,8 @@
       "properties": {
         "stroke-width": 4,
         "fill-opacity": 0.4,
-        "stroke": "green",
-        "fill": "green",
+        "stroke": "blue",
+        "fill": "blue",
         "pressure": 0.5
       },
       "geometry": {
@@ -620,8 +620,8 @@
       "properties": {
         "stroke-width": 4,
         "fill-opacity": 0.4,
-        "stroke": "yellow",
-        "fill": "yellow",
+        "stroke": "green",
+        "fill": "green",
         "pressure": 1.5
       },
       "geometry": {
@@ -964,8 +964,8 @@
       "properties": {
         "stroke-width": 4,
         "fill-opacity": 0.4,
-        "stroke": "red",
-        "fill": "red",
+        "stroke": "yellow",
+        "fill": "yellow",
         "pressure": 2.5
       },
       "geometry": {
@@ -1162,12 +1162,11 @@
       "properties": {
         "stroke-width": 4,
         "fill-opacity": 0.4,
+        "stroke": "red",
+        "fill": "red",
         "pressure": 100
       },
-      "geometry": {
-        "type": "MultiLineString",
-        "coordinates": []
-      }
+      "geometry": { "type": "MultiLineString", "coordinates": [] }
     },
     {
       "type": "Feature",
diff --git a/packages/turf-isolines/test/out/matrix1.geojson b/packages/turf-isolines/test/out/matrix1.geojson
index e245719583..b67dfba6ac 100644
--- a/packages/turf-isolines/test/out/matrix1.geojson
+++ b/packages/turf-isolines/test/out/matrix1.geojson
@@ -3,9 +3,37 @@
   "features": [
     {
       "type": "Feature",
-      "properties": {
-        "temperature": 4
-      },
+      "properties": { "temperature": 2 },
+      "geometry": {
+        "type": "MultiLineString",
+        "coordinates": [
+          [
+            [10.863591, 44.279864],
+            [11.054363, 44.144966],
+            [11.308726, 44.144966],
+            [11.56309, 44.144966],
+            [11.817453, 44.144966],
+            [12.071816, 44.144966],
+            [12.262588, 44.279864],
+            [12.262588, 44.459728],
+            [12.262588, 44.639592],
+            [12.262588, 44.819456],
+            [12.071816, 44.954354],
+            [11.817453, 44.954354],
+            [11.56309, 44.954354],
+            [11.308726, 44.954354],
+            [11.054363, 44.954354],
+            [10.863591, 44.819456],
+            [10.863591, 44.639592],
+            [10.863591, 44.459728],
+            [10.863591, 44.279864]
+          ]
+        ]
+      }
+    },
+    {
+      "type": "Feature",
+      "properties": { "temperature": 4 },
       "geometry": {
         "type": "MultiLineString",
         "coordinates": [
@@ -35,9 +63,7 @@
     },
     {
       "type": "Feature",
-      "properties": {
-        "temperature": 8
-      },
+      "properties": { "temperature": 8 },
       "geometry": {
         "type": "MultiLineString",
         "coordinates": [
@@ -59,9 +85,7 @@
     },
     {
       "type": "Feature",
-      "properties": {
-        "temperature": 12
-      },
+      "properties": { "temperature": 12 },
       "geometry": {
         "type": "MultiLineString",
         "coordinates": [
diff --git a/packages/turf-isolines/test/out/matrix2.geojson b/packages/turf-isolines/test/out/matrix2.geojson
index 6d9c5ed85e..6e09eb3644 100644
--- a/packages/turf-isolines/test/out/matrix2.geojson
+++ b/packages/turf-isolines/test/out/matrix2.geojson
@@ -7,7 +7,7 @@
         "stroke-width": 3,
         "stroke": "darkred",
         "fill": "darkred",
-        "fill-opacity": 0.5,
+        "fill-opacity": 0.4,
         "elevation": 4.5
       },
       "geometry": {
@@ -56,7 +56,7 @@
         "stroke-width": 3,
         "stroke": "darkred",
         "fill": "darkred",
-        "fill-opacity": 0.7,
+        "fill-opacity": 0.5,
         "elevation": 9
       },
       "geometry": {
@@ -105,7 +105,7 @@
         "stroke-width": 3,
         "stroke": "darkred",
         "fill": "darkred",
-        "fill-opacity": 0.8,
+        "fill-opacity": 0.7,
         "elevation": 13.5
       },
       "geometry": {
@@ -136,6 +136,7 @@
         "stroke-width": 3,
         "stroke": "darkred",
         "fill": "darkred",
+        "fill-opacity": 0.8,
         "elevation": 18
       },
       "geometry": {
diff --git a/packages/turf-isolines/test/out/pointGrid.geojson b/packages/turf-isolines/test/out/pointGrid.geojson
index 9d55c33376..24faca3dcd 100644
--- a/packages/turf-isolines/test/out/pointGrid.geojson
+++ b/packages/turf-isolines/test/out/pointGrid.geojson
@@ -3,10 +3,7 @@
   "features": [
     {
       "type": "Feature",
-      "properties": {
-        "fill-opacity": 0.6,
-        "population": 20
-      },
+      "properties": { "fill-opacity": 0.5, "population": 20 },
       "geometry": {
         "type": "MultiLineString",
         "coordinates": [
@@ -66,10 +63,7 @@
     },
     {
       "type": "Feature",
-      "properties": {
-        "fill-opacity": 0.7,
-        "population": 40
-      },
+      "properties": { "fill-opacity": 0.6, "population": 40 },
       "geometry": {
         "type": "MultiLineString",
         "coordinates": [
@@ -133,10 +127,7 @@
     },
     {
       "type": "Feature",
-      "properties": {
-        "fill-opacity": 0.8,
-        "population": 80
-      },
+      "properties": { "fill-opacity": 0.7, "population": 80 },
       "geometry": {
         "type": "MultiLineString",
         "coordinates": [
@@ -162,13 +153,8 @@
     },
     {
       "type": "Feature",
-      "properties": {
-        "population": 160
-      },
-      "geometry": {
-        "type": "MultiLineString",
-        "coordinates": []
-      }
+      "properties": { "fill-opacity": 0.8, "population": 160 },
+      "geometry": { "type": "MultiLineString", "coordinates": [] }
     },
     {
       "type": "Feature",