diff --git a/src/traces/sunburst/plot.js b/src/traces/sunburst/plot.js
index e0792ce1aad..df35feb912a 100644
--- a/src/traces/sunburst/plot.js
+++ b/src/traces/sunburst/plot.js
@@ -797,7 +797,7 @@ function determineInsideTextFont(trace, pt, layoutFont) {
 }
 
 function getInscribedRadiusFraction(pt) {
-    if(pt.rpx0 === 0 && pt.xmid === Math.PI) {
+    if(pt.rpx0 === 0 && Lib.isFullCircle([pt.x0, pt.x1])) {
         // special case of 100% with no hole
         return 1;
     } else {
diff --git a/test/image/baselines/sunburst_textfit.png b/test/image/baselines/sunburst_textfit.png
new file mode 100644
index 00000000000..495029d2378
Binary files /dev/null and b/test/image/baselines/sunburst_textfit.png differ
diff --git a/test/image/mocks/sunburst_textfit.json b/test/image/mocks/sunburst_textfit.json
new file mode 100644
index 00000000000..0f21a58e62f
--- /dev/null
+++ b/test/image/mocks/sunburst_textfit.json
@@ -0,0 +1,86 @@
+{
+  "data": [
+    {
+      "type": "sunburst",
+      "ids": [
+        "Parent Name One",
+        "Parent Name Two",
+        "Parent Name Three",
+        "Parent Name Four",
+        "Parent Name Five",
+        "Parent Name Six",
+        "Parent Name Seven",
+        "Parent Name One-Child 1",
+        "Parent Name Two-Child 2",
+        "Parent Name Two-Child 3",
+        "Parent Name Two-Child 4",
+        "Parent Name Two-Child 5",
+        "Parent Name Three-Child 6",
+        "Parent Name Three-Child 7",
+        "Parent Name Four-Child 8",
+        "Parent Name Four-Child 9",
+        "Parent Name Five-Child 10",
+        "Parent Name Five-Child 11",
+        "Parent Name Five-Child 12",
+        "Parent Name Six-Child 13",
+        "Parent Name Six-Child 14",
+        "Parent Name Seven-Child 15",
+        "Parent Name Seven-Child 16",
+        "Parent Name Seven-Child 17"
+      ],
+      "labels": [
+        "Parent Name One",
+        "Parent Name Two",
+        "Parent Name Three",
+        "Parent Name Four",
+        "Parent Name Five",
+        "Parent Name Six",
+        "Parent Name Seven",
+        "Child 1",
+        "Child 2",
+        "Child 3",
+        "Child 4",
+        "Child 5",
+        "Child 6",
+        "Child 7",
+        "Child 8",
+        "Child 9",
+        "Child 10",
+        "Child 11",
+        "Child 12",
+        "Child 13",
+        "Child 14",
+        "Child 15",
+        "Child 16",
+        "Child 17"
+      ],
+      "parents": [
+        "",
+        "",
+        "",
+        "",
+        "",
+        "",
+        "",
+        "Parent Name One",
+        "Parent Name Two",
+        "Parent Name Two",
+        "Parent Name Two",
+        "Parent Name Two",
+        "Parent Name Three",
+        "Parent Name Three",
+        "Parent Name Four",
+        "Parent Name Four",
+        "Parent Name Five",
+        "Parent Name Five",
+        "Parent Name Five",
+        "Parent Name Six",
+        "Parent Name Six",
+        "Parent Name Seven",
+        "Parent Name Seven",
+        "Parent Name Seven"
+      ]
+    }
+  ],
+  "layout": {}
+}