diff --git a/src/traces/sunburst/calc.js b/src/traces/sunburst/calc.js
index e8a9a90d676..cb098662e5b 100644
--- a/src/traces/sunburst/calc.js
+++ b/src/traces/sunburst/calc.js
@@ -111,7 +111,10 @@ exports.calc = function(gd, trace) {
                 label: k
             });
         } else {
-            return Lib.warn('Multiple implied roots, cannot build ' + trace.type + ' hierarchy.');
+            return Lib.warn([
+                'Multiple implied roots, cannot build', trace.type, 'hierarchy of', trace.name + '.',
+                'These roots include:', impliedRoots.join(', ')
+            ].join(' '));
         }
     } else if(parent2children[''].length > 1) {
         var dummyId = Lib.randstr();
@@ -140,7 +143,10 @@ exports.calc = function(gd, trace) {
             .id(function(d) { return d.id; })
             .parentId(function(d) { return d.pid; })(cd);
     } catch(e) {
-        return Lib.warn('Failed to build ' + trace.type + ' hierarchy. Error: ' + e.message);
+        return Lib.warn([
+            'Failed to build', trace.type, 'hierarchy of', trace.name + '.',
+            'Error:', e.message
+        ].join(' '));
     }
 
     var hierarchy = d3Hierarchy.hierarchy(root);
@@ -170,7 +176,7 @@ exports.calc = function(gd, trace) {
                         if(v < partialSum * ALMOST_EQUAL) {
                             failed = true;
                             return Lib.warn([
-                                'Total value for node', d.data.data.id,
+                                'Total value for node', d.data.data.id, 'of', trace.name,
                                 'is smaller than the sum of its children.',
                                 '\nparent value =', v,
                                 '\nchildren sum =', partialSum
diff --git a/test/jasmine/tests/sunburst_test.js b/test/jasmine/tests/sunburst_test.js
index d78ee444c64..a59bb2e57fb 100644
--- a/test/jasmine/tests/sunburst_test.js
+++ b/test/jasmine/tests/sunburst_test.js
@@ -248,7 +248,7 @@ describe('Test sunburst calc:', function() {
         });
 
         expect(Lib.warn).toHaveBeenCalledTimes(1);
-        expect(Lib.warn).toHaveBeenCalledWith('Multiple implied roots, cannot build sunburst hierarchy.');
+        expect(Lib.warn).toHaveBeenCalledWith('Multiple implied roots, cannot build sunburst hierarchy of trace 0. These roots include: Root1, Root22');
     });
 
     it('should generate "root of roots" when it can', function() {
@@ -299,8 +299,8 @@ describe('Test sunburst calc:', function() {
         expect(gd.calcdata[0][0].hierarchy).toBe(undefined, 'no computed hierarchy');
 
         expect(Lib.warn).toHaveBeenCalledTimes(2);
-        expect(Lib.warn.calls.allArgs()[0][0]).toBe('Total value for node Root is smaller than the sum of its children. \nparent value = 0 \nchildren sum = 3');
-        expect(Lib.warn.calls.allArgs()[1][0]).toBe('Total value for node B is smaller than the sum of its children. \nparent value = 2 \nchildren sum = 3');
+        expect(Lib.warn.calls.allArgs()[0][0]).toBe('Total value for node Root of trace 0 is smaller than the sum of its children. \nparent value = 0 \nchildren sum = 3');
+        expect(Lib.warn.calls.allArgs()[1][0]).toBe('Total value for node B of trace 0 is smaller than the sum of its children. \nparent value = 2 \nchildren sum = 3');
     });
 
     it('should warn labels/parents lead to ambiguous hierarchy', function() {
@@ -310,7 +310,7 @@ describe('Test sunburst calc:', function() {
         });
 
         expect(Lib.warn).toHaveBeenCalledTimes(1);
-        expect(Lib.warn).toHaveBeenCalledWith('Failed to build sunburst hierarchy. Error: ambiguous: A');
+        expect(Lib.warn).toHaveBeenCalledWith('Failed to build sunburst hierarchy of trace 0. Error: ambiguous: A');
     });
 
     it('should warn ids/parents lead to ambiguous hierarchy', function() {
@@ -321,7 +321,7 @@ describe('Test sunburst calc:', function() {
         });
 
         expect(Lib.warn).toHaveBeenCalledTimes(1);
-        expect(Lib.warn).toHaveBeenCalledWith('Failed to build sunburst hierarchy. Error: ambiguous: b');
+        expect(Lib.warn).toHaveBeenCalledWith('Failed to build sunburst hierarchy of trace 0. Error: ambiguous: b');
     });
 
     it('should accept numbers (even `0`) are ids/parents items', function() {
diff --git a/test/jasmine/tests/treemap_test.js b/test/jasmine/tests/treemap_test.js
index f5788260b2d..52374fc3cc4 100644
--- a/test/jasmine/tests/treemap_test.js
+++ b/test/jasmine/tests/treemap_test.js
@@ -363,7 +363,7 @@ describe('Test treemap calc:', function() {
         });
 
         expect(Lib.warn).toHaveBeenCalledTimes(1);
-        expect(Lib.warn).toHaveBeenCalledWith('Multiple implied roots, cannot build treemap hierarchy.');
+        expect(Lib.warn).toHaveBeenCalledWith('Multiple implied roots, cannot build treemap hierarchy of trace 0. These roots include: Root1, Root22');
     });
 
     it('should generate "root of roots" when it can', function() {
@@ -414,8 +414,8 @@ describe('Test treemap calc:', function() {
         expect(gd.calcdata[0][0].hierarchy).toBe(undefined, 'no computed hierarchy');
 
         expect(Lib.warn).toHaveBeenCalledTimes(2);
-        expect(Lib.warn.calls.allArgs()[0][0]).toBe('Total value for node Root is smaller than the sum of its children. \nparent value = 0 \nchildren sum = 3');
-        expect(Lib.warn.calls.allArgs()[1][0]).toBe('Total value for node B is smaller than the sum of its children. \nparent value = 2 \nchildren sum = 3');
+        expect(Lib.warn.calls.allArgs()[0][0]).toBe('Total value for node Root of trace 0 is smaller than the sum of its children. \nparent value = 0 \nchildren sum = 3');
+        expect(Lib.warn.calls.allArgs()[1][0]).toBe('Total value for node B of trace 0 is smaller than the sum of its children. \nparent value = 2 \nchildren sum = 3');
     });
 
     it('should warn labels/parents lead to ambiguous hierarchy', function() {
@@ -425,7 +425,7 @@ describe('Test treemap calc:', function() {
         });
 
         expect(Lib.warn).toHaveBeenCalledTimes(1);
-        expect(Lib.warn).toHaveBeenCalledWith('Failed to build treemap hierarchy. Error: ambiguous: A');
+        expect(Lib.warn).toHaveBeenCalledWith('Failed to build treemap hierarchy of trace 0. Error: ambiguous: A');
     });
 
     it('should warn ids/parents lead to ambiguous hierarchy', function() {
@@ -436,7 +436,7 @@ describe('Test treemap calc:', function() {
         });
 
         expect(Lib.warn).toHaveBeenCalledTimes(1);
-        expect(Lib.warn).toHaveBeenCalledWith('Failed to build treemap hierarchy. Error: ambiguous: b');
+        expect(Lib.warn).toHaveBeenCalledWith('Failed to build treemap hierarchy of trace 0. Error: ambiguous: b');
     });
 
     it('should accept numbers (even `0`) are ids/parents items', function() {