diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index e990c0f675c32..19855c5ac6305 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -4685,12 +4685,20 @@ namespace ts {
                 && lookAhead(nextTokenIsIdentifierOrKeywordOrOpenBracketOrTemplate);
         }
 
+        function hasOptionalChain(node: Node) {
+            while (true) {
+                if (node.flags & NodeFlags.OptionalChain) return true;
+                if (!isNonNullExpression(node)) return false;
+                node = node.expression;
+            }
+        }
+
         function parsePropertyAccessExpressionRest(expression: LeftHandSideExpression, questionDotToken: QuestionDotToken | undefined) {
             const propertyAccess = <PropertyAccessExpression>createNode(SyntaxKind.PropertyAccessExpression, expression.pos);
             propertyAccess.expression = expression;
             propertyAccess.questionDotToken = questionDotToken;
             propertyAccess.name = parseRightSideOfDot(/*allowIdentifierNames*/ true, /*allowPrivateIdentifiers*/ true);
-            if (questionDotToken || expression.flags & NodeFlags.OptionalChain) {
+            if (questionDotToken || hasOptionalChain(expression)) {
                 propertyAccess.flags |= NodeFlags.OptionalChain;
                 if (isPrivateIdentifier(propertyAccess.name)) {
                     parseErrorAtRange(propertyAccess.name, Diagnostics.An_optional_chain_cannot_contain_private_identifiers);
@@ -4716,7 +4724,7 @@ namespace ts {
             }
 
             parseExpected(SyntaxKind.CloseBracketToken);
-            if (questionDotToken || expression.flags & NodeFlags.OptionalChain) {
+            if (questionDotToken || hasOptionalChain(expression)) {
                 indexedAccess.flags |= NodeFlags.OptionalChain;
             }
             return finishNode(indexedAccess);
@@ -4803,7 +4811,7 @@ namespace ts {
                         callExpr.questionDotToken = questionDotToken;
                         callExpr.typeArguments = typeArguments;
                         callExpr.arguments = parseArgumentList();
-                        if (questionDotToken || expression.flags & NodeFlags.OptionalChain) {
+                        if (questionDotToken || hasOptionalChain(expression)) {
                             callExpr.flags |= NodeFlags.OptionalChain;
                         }
                         expression = finishNode(callExpr);
@@ -4815,7 +4823,7 @@ namespace ts {
                     callExpr.expression = expression;
                     callExpr.questionDotToken = questionDotToken;
                     callExpr.arguments = parseArgumentList();
-                    if (questionDotToken || expression.flags & NodeFlags.OptionalChain) {
+                    if (questionDotToken || hasOptionalChain(expression)) {
                         callExpr.flags |= NodeFlags.OptionalChain;
                     }
                     expression = finishNode(callExpr);
diff --git a/src/compiler/transformers/es2020.ts b/src/compiler/transformers/es2020.ts
index bc5ea6771e6cb..e70ac12aa1b5d 100644
--- a/src/compiler/transformers/es2020.ts
+++ b/src/compiler/transformers/es2020.ts
@@ -44,7 +44,7 @@ namespace ts {
       function flattenChain(chain: OptionalChain) {
           const links: OptionalChain[] = [chain];
           while (!chain.questionDotToken && !isTaggedTemplateExpression(chain)) {
-              chain = cast(chain.expression, isOptionalChain);
+              chain = cast(skipPartiallyEmittedExpressions(chain.expression), isOptionalChain);
               links.unshift(chain);
           }
           return { expression: chain.expression, chain: links };
diff --git a/tests/baselines/reference/callChain.js b/tests/baselines/reference/callChain.js
index f67166dcde372..0b26ed119d07e 100644
--- a/tests/baselines/reference/callChain.js
+++ b/tests/baselines/reference/callChain.js
@@ -35,7 +35,10 @@ const v: number | undefined = o4?.(incr);
 
 // GH#33744
 declare const o5: <T>() => undefined | (() => void);
-o5<number>()?.();
+o5<number>()?.();
+
+// GH#36031
+o2?.b()!.toString
 
 //// [callChain.js]
 "use strict";
@@ -73,3 +76,5 @@ o2 === null || o2 === void 0 ? void 0 : o2["b"].apply(o2, __spreadArrays([1], [2
 (_m = o3["b"]) === null || _m === void 0 ? void 0 : _m.call.apply(_m, __spreadArrays([o3, 1], [2, 3], [4])).c;
 var v = o4 === null || o4 === void 0 ? void 0 : o4(incr);
 (_o = o5()) === null || _o === void 0 ? void 0 : _o();
+// GH#36031
+o2 === null || o2 === void 0 ? void 0 : o2.b().toString;
diff --git a/tests/baselines/reference/callChain.symbols b/tests/baselines/reference/callChain.symbols
index d0a266c41ea42..841c34679e37d 100644
--- a/tests/baselines/reference/callChain.symbols
+++ b/tests/baselines/reference/callChain.symbols
@@ -156,3 +156,11 @@ declare const o5: <T>() => undefined | (() => void);
 o5<number>()?.();
 >o5 : Symbol(o5, Decl(callChain.ts, 35, 13))
 
+// GH#36031
+o2?.b()!.toString
+>o2?.b()!.toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+>o2?.b : Symbol(b, Decl(callChain.ts, 6, 31))
+>o2 : Symbol(o2, Decl(callChain.ts, 6, 13))
+>b : Symbol(b, Decl(callChain.ts, 6, 31))
+>toString : Symbol(Number.toString, Decl(lib.es5.d.ts, --, --))
+
diff --git a/tests/baselines/reference/callChain.types b/tests/baselines/reference/callChain.types
index 6ba17855cb3e1..d511b77869f06 100644
--- a/tests/baselines/reference/callChain.types
+++ b/tests/baselines/reference/callChain.types
@@ -264,3 +264,13 @@ o5<number>()?.();
 >o5<number>() : (() => void) | undefined
 >o5 : <T>() => (() => void) | undefined
 
+// GH#36031
+o2?.b()!.toString
+>o2?.b()!.toString : (radix?: number | undefined) => string
+>o2?.b()! : number
+>o2?.b() : number | undefined
+>o2?.b : ((...args: any[]) => number) | undefined
+>o2 : { b: (...args: any[]) => number; } | undefined
+>b : ((...args: any[]) => number) | undefined
+>toString : (radix?: number | undefined) => string
+
diff --git a/tests/baselines/reference/elementAccessChain.js b/tests/baselines/reference/elementAccessChain.js
index 5dd4e79b918f3..c700d392795ef 100644
--- a/tests/baselines/reference/elementAccessChain.js
+++ b/tests/baselines/reference/elementAccessChain.js
@@ -22,7 +22,11 @@ o5["b"]?.()["c"].d?.["e"];
 
 // GH#33744
 declare const o6: <T>() => undefined | ({ x: number });
-o6<number>()?.["x"];
+o6<number>()?.["x"];
+
+// GH#36031
+o2?.["b"]!.c
+o2?.["b"]!["c"]
 
 //// [elementAccessChain.js]
 "use strict";
@@ -39,3 +43,6 @@ o2 === null || o2 === void 0 ? void 0 : o2.b["c"];
 (_m = (_l = o5["b"]) === null || _l === void 0 ? void 0 : _l.call(o5)["c"].d) === null || _m === void 0 ? void 0 : _m.e;
 (_p = (_o = o5["b"]) === null || _o === void 0 ? void 0 : _o.call(o5)["c"].d) === null || _p === void 0 ? void 0 : _p["e"];
 (_q = o6()) === null || _q === void 0 ? void 0 : _q["x"];
+// GH#36031
+o2 === null || o2 === void 0 ? void 0 : o2["b"].c;
+o2 === null || o2 === void 0 ? void 0 : o2["b"]["c"];
diff --git a/tests/baselines/reference/elementAccessChain.symbols b/tests/baselines/reference/elementAccessChain.symbols
index 5e892012173fc..9224498f5b427 100644
--- a/tests/baselines/reference/elementAccessChain.symbols
+++ b/tests/baselines/reference/elementAccessChain.symbols
@@ -106,3 +106,13 @@ declare const o6: <T>() => undefined | ({ x: number });
 o6<number>()?.["x"];
 >o6 : Symbol(o6, Decl(elementAccessChain.ts, 22, 13))
 
+// GH#36031
+o2?.["b"]!.c
+>o2?.["b"]!.c : Symbol(c, Decl(elementAccessChain.ts, 3, 36))
+>o2 : Symbol(o2, Decl(elementAccessChain.ts, 3, 13))
+>c : Symbol(c, Decl(elementAccessChain.ts, 3, 36))
+
+o2?.["b"]!["c"]
+>o2 : Symbol(o2, Decl(elementAccessChain.ts, 3, 13))
+>"c" : Symbol(c, Decl(elementAccessChain.ts, 3, 36))
+
diff --git a/tests/baselines/reference/elementAccessChain.types b/tests/baselines/reference/elementAccessChain.types
index a186074e86bed..db9833253ec37 100644
--- a/tests/baselines/reference/elementAccessChain.types
+++ b/tests/baselines/reference/elementAccessChain.types
@@ -141,3 +141,20 @@ o6<number>()?.["x"];
 >o6 : <T>() => { x: number; } | undefined
 >"x" : "x"
 
+// GH#36031
+o2?.["b"]!.c
+>o2?.["b"]!.c : string
+>o2?.["b"]! : { c: string; }
+>o2?.["b"] : { c: string; } | undefined
+>o2 : { b: { c: string; }; } | undefined
+>"b" : "b"
+>c : string
+
+o2?.["b"]!["c"]
+>o2?.["b"]!["c"] : string
+>o2?.["b"]! : { c: string; }
+>o2?.["b"] : { c: string; } | undefined
+>o2 : { b: { c: string; }; } | undefined
+>"b" : "b"
+>"c" : "c"
+
diff --git a/tests/baselines/reference/propertyAccessChain.js b/tests/baselines/reference/propertyAccessChain.js
index a2ece64f98690..4f90fd4d75f24 100644
--- a/tests/baselines/reference/propertyAccessChain.js
+++ b/tests/baselines/reference/propertyAccessChain.js
@@ -19,7 +19,10 @@ declare const o6: <T>() => undefined | ({ x: number });
 o6<number>()?.x;
 
 // GH#34109
-o1?.b ? 1 : 0;
+o1?.b ? 1 : 0;
+
+// GH#36031
+o2?.b!.c
 
 //// [propertyAccessChain.js]
 "use strict";
@@ -32,3 +35,5 @@ o2 === null || o2 === void 0 ? void 0 : o2.b.c;
 (_f = o6()) === null || _f === void 0 ? void 0 : _f.x;
 // GH#34109
 (o1 === null || o1 === void 0 ? void 0 : o1.b) ? 1 : 0;
+// GH#36031
+o2 === null || o2 === void 0 ? void 0 : o2.b.c;
diff --git a/tests/baselines/reference/propertyAccessChain.symbols b/tests/baselines/reference/propertyAccessChain.symbols
index 21f694a57f903..e97c1700a5f9d 100644
--- a/tests/baselines/reference/propertyAccessChain.symbols
+++ b/tests/baselines/reference/propertyAccessChain.symbols
@@ -85,3 +85,11 @@ o1?.b ? 1 : 0;
 >o1 : Symbol(o1, Decl(propertyAccessChain.ts, 0, 13))
 >b : Symbol(b, Decl(propertyAccessChain.ts, 0, 31))
 
+// GH#36031
+o2?.b!.c
+>o2?.b!.c : Symbol(c, Decl(propertyAccessChain.ts, 3, 36))
+>o2?.b : Symbol(b, Decl(propertyAccessChain.ts, 3, 31))
+>o2 : Symbol(o2, Decl(propertyAccessChain.ts, 3, 13))
+>b : Symbol(b, Decl(propertyAccessChain.ts, 3, 31))
+>c : Symbol(c, Decl(propertyAccessChain.ts, 3, 36))
+
diff --git a/tests/baselines/reference/propertyAccessChain.types b/tests/baselines/reference/propertyAccessChain.types
index 60428ac5c1eb7..e4b193eb7ef33 100644
--- a/tests/baselines/reference/propertyAccessChain.types
+++ b/tests/baselines/reference/propertyAccessChain.types
@@ -89,3 +89,12 @@ o1?.b ? 1 : 0;
 >1 : 1
 >0 : 0
 
+// GH#36031
+o2?.b!.c
+>o2?.b!.c : string
+>o2?.b! : { c: string; }
+>o2?.b : { c: string; } | undefined
+>o2 : { b: { c: string; }; } | undefined
+>b : { c: string; } | undefined
+>c : string
+
diff --git a/tests/cases/conformance/expressions/optionalChaining/callChain/callChain.ts b/tests/cases/conformance/expressions/optionalChaining/callChain/callChain.ts
index bbfc3aa42f929..f0c5f5179bcc3 100644
--- a/tests/cases/conformance/expressions/optionalChaining/callChain/callChain.ts
+++ b/tests/cases/conformance/expressions/optionalChaining/callChain/callChain.ts
@@ -36,4 +36,7 @@ const v: number | undefined = o4?.(incr);
 
 // GH#33744
 declare const o5: <T>() => undefined | (() => void);
-o5<number>()?.();
\ No newline at end of file
+o5<number>()?.();
+
+// GH#36031
+o2?.b()!.toString
\ No newline at end of file
diff --git a/tests/cases/conformance/expressions/optionalChaining/elementAccessChain/elementAccessChain.ts b/tests/cases/conformance/expressions/optionalChaining/elementAccessChain/elementAccessChain.ts
index 20dfaab0c86d7..f525e8cb3111e 100644
--- a/tests/cases/conformance/expressions/optionalChaining/elementAccessChain/elementAccessChain.ts
+++ b/tests/cases/conformance/expressions/optionalChaining/elementAccessChain/elementAccessChain.ts
@@ -23,4 +23,8 @@ o5["b"]?.()["c"].d?.["e"];
 
 // GH#33744
 declare const o6: <T>() => undefined | ({ x: number });
-o6<number>()?.["x"];
\ No newline at end of file
+o6<number>()?.["x"];
+
+// GH#36031
+o2?.["b"]!.c
+o2?.["b"]!["c"]
\ No newline at end of file
diff --git a/tests/cases/conformance/expressions/optionalChaining/propertyAccessChain/propertyAccessChain.ts b/tests/cases/conformance/expressions/optionalChaining/propertyAccessChain/propertyAccessChain.ts
index 1f9e0bc0550c8..96b89bb30b9cd 100644
--- a/tests/cases/conformance/expressions/optionalChaining/propertyAccessChain/propertyAccessChain.ts
+++ b/tests/cases/conformance/expressions/optionalChaining/propertyAccessChain/propertyAccessChain.ts
@@ -20,4 +20,7 @@ declare const o6: <T>() => undefined | ({ x: number });
 o6<number>()?.x;
 
 // GH#34109
-o1?.b ? 1 : 0;
\ No newline at end of file
+o1?.b ? 1 : 0;
+
+// GH#36031
+o2?.b!.c
\ No newline at end of file