diff --git a/src/services/services.ts b/src/services/services.ts
index af61e342a8e..8b4986e8ba4 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -2843,7 +2843,8 @@ module ts {
                     if (signatureDeclaration.kind === SyntaxKind.ConstructSignature) {
                         displayParts.push(keywordPart(SyntaxKind.NewKeyword));
                         displayParts.push(spacePart());
-                    } else if (signatureDeclaration.kind !== SyntaxKind.CallSignature) {
+                    }
+                    else if (signatureDeclaration.kind !== SyntaxKind.CallSignature && signatureDeclaration.name) {
                         displayParts.push.apply(displayParts, symbolToDisplayParts(typeResolver, signatureDeclaration.symbol, sourceFile, /*meaning*/ undefined, SymbolFormatFlags.WriteTypeParametersOrArguments))
                     }
                     displayParts.push.apply(displayParts, signatureToDisplayParts(typeResolver, signature, sourceFile, TypeFormatFlags.NoTruncation | TypeFormatFlags.WriteTypeArgumentsOfSignature));
diff --git a/tests/cases/fourslash_old/completionBeforeSemanticDiagnosticsInArrowFunction1.ts b/tests/cases/fourslash/completionBeforeSemanticDiagnosticsInArrowFunction1.ts
similarity index 80%
rename from tests/cases/fourslash_old/completionBeforeSemanticDiagnosticsInArrowFunction1.ts
rename to tests/cases/fourslash/completionBeforeSemanticDiagnosticsInArrowFunction1.ts
index b5475fe263f..bc0aa713880 100644
--- a/tests/cases/fourslash_old/completionBeforeSemanticDiagnosticsInArrowFunction1.ts
+++ b/tests/cases/fourslash/completionBeforeSemanticDiagnosticsInArrowFunction1.ts
@@ -15,7 +15,7 @@ fs.edit.insert("A");
 // Bring up completion to force a pull resolve.  This will end up resolving several symbols and
 // producing unreported diagnostics (i.e. that 'V' wasn't found).
 fs.verify.completionListContains("T");
-fs.verify.completionEntryDetailIs("T", "T in <T>(x: T): void");
+fs.verify.completionEntryDetailIs("T", "(type parameter) T in <T>(x: any): void");
 
 // There should now be a single error.
 fs.verify.numberOfErrorsInCurrentFile(1);
\ No newline at end of file