diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 57603c461ef..df5356e7332 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -4074,8 +4074,8 @@ module ts {
                     }
                 }
                 else if (source.flags & TypeFlags.TypeParameter && sourceOrApparentType.flags & TypeFlags.Union) {
-                    if (result = isRelatedTo(sourceOrApparentType, <ObjectType>target, reportStructuralErrors)) {
-                        errorInfo = saveErrorInfo;
+                    errorInfo = saveErrorInfo;
+                    if (result = isRelatedTo(sourceOrApparentType, target, reportErrors)) {
                         return result;
                     }
                 }
diff --git a/tests/baselines/reference/typeParameterDiamond3.errors.txt b/tests/baselines/reference/typeParameterDiamond3.errors.txt
index 2ef46ec2f8b..abefeb2a2d9 100644
--- a/tests/baselines/reference/typeParameterDiamond3.errors.txt
+++ b/tests/baselines/reference/typeParameterDiamond3.errors.txt
@@ -1,8 +1,8 @@
 tests/cases/compiler/typeParameterDiamond3.ts(8,13): error TS2322: Type 'T | U' is not assignable to type 'Top'.
   Type 'T' is not assignable to type 'Top'.
 tests/cases/compiler/typeParameterDiamond3.ts(9,13): error TS2322: Type 'Bottom' is not assignable to type 'T | U'.
-  Type 'Bottom' is not assignable to type 'U'.
-    Type 'Top | T | U' is not assignable to type 'U'.
+  Type 'Top | T | U' is not assignable to type 'T | U'.
+    Type 'Top' is not assignable to type 'T | U'.
       Type 'Top' is not assignable to type 'U'.
 tests/cases/compiler/typeParameterDiamond3.ts(10,13): error TS2322: Type 'Bottom' is not assignable to type 'Top'.
   Type 'Top | T | U' is not assignable to type 'Top'.
@@ -24,8 +24,8 @@ tests/cases/compiler/typeParameterDiamond3.ts(10,13): error TS2322: Type 'Bottom
                 middle = bottom;
                 ~~~~~~
 !!! error TS2322: Type 'Bottom' is not assignable to type 'T | U'.
-!!! error TS2322:   Type 'Bottom' is not assignable to type 'U'.
-!!! error TS2322:     Type 'Top | T | U' is not assignable to type 'U'.
+!!! error TS2322:   Type 'Top | T | U' is not assignable to type 'T | U'.
+!!! error TS2322:     Type 'Top' is not assignable to type 'T | U'.
 !!! error TS2322:       Type 'Top' is not assignable to type 'U'.
                 top = bottom;
                 ~~~