diff --git a/src/services/formatting/rules.ts b/src/services/formatting/rules.ts
index 98b8be1fe8c..6931a6e5b44 100644
--- a/src/services/formatting/rules.ts
+++ b/src/services/formatting/rules.ts
@@ -106,7 +106,7 @@ export function getAllRules(): RuleSpec[] {
         rule("SpaceAfterQuestionMarkInConditionalOperator", SyntaxKind.QuestionToken, anyToken, [isNonJsxSameLineTokenContext, isConditionalOperatorContext], RuleAction.InsertSpace),
 
         // in other cases there should be no space between '?' and next token
-        rule("NoSpaceAfterQuestionMark", SyntaxKind.QuestionToken, anyToken, [isNonJsxSameLineTokenContext], RuleAction.DeleteSpace),
+        rule("NoSpaceAfterQuestionMark", SyntaxKind.QuestionToken, anyToken, [isNonJsxSameLineTokenContext, isNonOptionalPropertyContext], RuleAction.DeleteSpace),
 
         rule("NoSpaceBeforeDot", anyToken, [SyntaxKind.DotToken, SyntaxKind.QuestionDotToken], [isNonJsxSameLineTokenContext, isNotPropertyAccessOnIntegerLiteral], RuleAction.DeleteSpace),
         rule("NoSpaceAfterDot", [SyntaxKind.DotToken, SyntaxKind.QuestionDotToken], anyToken, [isNonJsxSameLineTokenContext], RuleAction.DeleteSpace),
@@ -561,6 +561,14 @@ function isTypeAnnotationContext(context: FormattingContext): boolean {
         isFunctionLikeKind(contextKind);
 }
 
+function isOptionalPropertyContext(context: FormattingContext) {
+    return isPropertyDeclaration(context.contextNode) && context.contextNode.questionToken;
+}
+
+function isNonOptionalPropertyContext(context: FormattingContext) {
+    return !isOptionalPropertyContext(context);
+}
+
 function isConditionalOperatorContext(context: FormattingContext): boolean {
     return context.contextNode.kind === SyntaxKind.ConditionalExpression ||
         context.contextNode.kind === SyntaxKind.ConditionalType;
diff --git a/tests/cases/fourslash/optionalPropertyFormatting.ts b/tests/cases/fourslash/optionalPropertyFormatting.ts
new file mode 100644
index 00000000000..141e691b14d
--- /dev/null
+++ b/tests/cases/fourslash/optionalPropertyFormatting.ts
@@ -0,0 +1,13 @@
+///<reference path="fourslash.ts"/>
+
+////export class C extends Error {
+////    message: string;
+////    data? = {};
+////}
+
+format.document();
+verify.currentFileContentIs(
+`export class C extends Error {
+    message: string;
+    data? = {};
+}`);