diff --git a/src/traces/table/data_preparation_helper.js b/src/traces/table/data_preparation_helper.js
index 5988cdd29e0..46253f97b56 100644
--- a/src/traces/table/data_preparation_helper.js
+++ b/src/traces/table/data_preparation_helper.js
@@ -10,6 +10,7 @@
 
 var c = require('./constants');
 var extendFlat = require('../../lib/extend').extendFlat;
+var isNumeric = require('fast-isnumeric');
 
 // pure functions, don't alter but passes on `gd` and parts of `trace` without deep copying
 module.exports = function calc(gd, trace) {
@@ -32,9 +33,10 @@ module.exports = function calc(gd, trace) {
     var uniqueKeys = {};
     var columnOrder = trace._fullInput.columnorder;
     var columnWidths = headerValues.map(function(d, i) {
-        return Array.isArray(trace.columnwidth) ?
+        var value = Array.isArray(trace.columnwidth) ?
             trace.columnwidth[Math.min(i, trace.columnwidth.length - 1)] :
-            isFinite(trace.columnwidth) && trace.columnwidth !== null ? trace.columnwidth : 1;
+            trace.columnwidth;
+        return isNumeric(value) ? Number(value) : 1;
     });
     var totalColumnWidths = columnWidths.reduce(function(p, n) {return p + n;}, 0);
 
diff --git a/test/image/mocks/table_plain_birds.json b/test/image/mocks/table_plain_birds.json
index df3355f94d6..45881c35bac 100644
--- a/test/image/mocks/table_plain_birds.json
+++ b/test/image/mocks/table_plain_birds.json
@@ -14,7 +14,7 @@
             "y": [0, 1]
         },
 
-        "columnwidth": [20, 40, 25, 25, 30, 20, 30],
+        "columnwidth": ["20", "40", "25", "25", "30", "20", "30"],
         "columnorder": [0, 1, 2, 3, 4, 5, 6],
 
         "header": {
diff --git a/test/jasmine/tests/table_test.js b/test/jasmine/tests/table_test.js
index 5e936838b1d..ddc2676d4cb 100644
--- a/test/jasmine/tests/table_test.js
+++ b/test/jasmine/tests/table_test.js
@@ -92,6 +92,20 @@ describe('table initialization tests', function() {
             expect(fullTrace.cells.values).toEqual([]);
         });
 
+        it('\'columnwidth\' specification should accept a numerical array', function() {
+            var fullTrace = _supply({
+                columnwidth: [1, 2, 3]
+            });
+            expect(fullTrace.columnwidth).toEqual([1, 2, 3]);
+        });
+
+        it('\'columnwidth\' specification should accept a string array (converted downstream)', function() {
+            var fullTrace = _supply({
+                columnwidth: ['1', '2', '3']
+            });
+            expect(fullTrace.columnwidth).toEqual(['1', '2', '3']);
+        });
+
         it('\'header\' should be used with default values where attributes are not provided', function() {
             var fullTrace = _supply({
                 header: {