diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 770e1a7c1c60a..8868a30354fa0 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -29297,6 +29297,11 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
 
         function narrowTypeByCallExpression(type: Type, callExpression: CallExpression, assumeTrue: boolean): Type {
             if (hasMatchingArgument(callExpression, reference)) {
+                // Ordinarily we don't need to to this in control flow analysis because the Binder breaks this down.
+                // However, we may encounter the need to narrow this down here when analyzing aliased conditional expressions.
+                if (inlineLevel !== 0 && isOptionalChain(callExpression)) {
+                    type = narrowTypeByOptionality(type, callExpression.expression, assumeTrue);
+                }
                 const signature = assumeTrue || !isCallChain(callExpression) ? getEffectsSignature(callExpression) : undefined;
                 const predicate = signature && getTypePredicateOfSignature(signature);
                 if (predicate && (predicate.kind === TypePredicateKind.This || predicate.kind === TypePredicateKind.Identifier)) {
@@ -29393,7 +29398,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
 
         function narrowTypeByOptionality(type: Type, expr: Expression, assumePresent: boolean): Type {
-            if (isMatchingReference(reference, expr)) {
+            if (isMatchingReference(reference, expr) || optionalChainContainsReference(expr, reference)) {
                 return getAdjustedTypeWithFacts(type, assumePresent ? TypeFacts.NEUndefinedOrNull : TypeFacts.EQUndefinedOrNull);
             }
             const access = getDiscriminantPropertyAccess(expr, type);
diff --git a/tests/baselines/reference/controlFlowOptionalChain5.symbols b/tests/baselines/reference/controlFlowOptionalChain5.symbols
new file mode 100644
index 0000000000000..7215cb3d81ab0
--- /dev/null
+++ b/tests/baselines/reference/controlFlowOptionalChain5.symbols
@@ -0,0 +1,39 @@
+//// [tests/cases/conformance/controlFlow/controlFlowOptionalChain5.ts] ////
+
+=== controlFlowOptionalChain5.ts ===
+// https://github.com/microsoft/TypeScript/issues/59145
+
+function resolve1(id: string | undefined) {
+>resolve1 : Symbol(resolve1, Decl(controlFlowOptionalChain5.ts, 0, 0))
+>id : Symbol(id, Decl(controlFlowOptionalChain5.ts, 2, 18))
+
+  const isBundled = id?.includes("_bundled");
+>isBundled : Symbol(isBundled, Decl(controlFlowOptionalChain5.ts, 3, 7))
+>id?.includes : Symbol(String.includes, Decl(lib.es2015.core.d.ts, --, --))
+>id : Symbol(id, Decl(controlFlowOptionalChain5.ts, 2, 18))
+>includes : Symbol(String.includes, Decl(lib.es2015.core.d.ts, --, --))
+
+  if (isBundled) {
+>isBundled : Symbol(isBundled, Decl(controlFlowOptionalChain5.ts, 3, 7))
+
+    const str: string = id;
+>str : Symbol(str, Decl(controlFlowOptionalChain5.ts, 5, 9))
+>id : Symbol(id, Decl(controlFlowOptionalChain5.ts, 2, 18))
+  }
+}
+
+function resolve2(id: string | undefined) {
+>resolve2 : Symbol(resolve2, Decl(controlFlowOptionalChain5.ts, 7, 1))
+>id : Symbol(id, Decl(controlFlowOptionalChain5.ts, 9, 18))
+
+  if (id?.includes("_bundled")) {
+>id?.includes : Symbol(String.includes, Decl(lib.es2015.core.d.ts, --, --))
+>id : Symbol(id, Decl(controlFlowOptionalChain5.ts, 9, 18))
+>includes : Symbol(String.includes, Decl(lib.es2015.core.d.ts, --, --))
+
+    const str: string = id;
+>str : Symbol(str, Decl(controlFlowOptionalChain5.ts, 11, 9))
+>id : Symbol(id, Decl(controlFlowOptionalChain5.ts, 9, 18))
+  }
+}
+
diff --git a/tests/baselines/reference/controlFlowOptionalChain5.types b/tests/baselines/reference/controlFlowOptionalChain5.types
new file mode 100644
index 0000000000000..1ecb4d3dc2678
--- /dev/null
+++ b/tests/baselines/reference/controlFlowOptionalChain5.types
@@ -0,0 +1,63 @@
+//// [tests/cases/conformance/controlFlow/controlFlowOptionalChain5.ts] ////
+
+=== controlFlowOptionalChain5.ts ===
+// https://github.com/microsoft/TypeScript/issues/59145
+
+function resolve1(id: string | undefined) {
+>resolve1 : (id: string | undefined) => void
+>         : ^  ^^                  ^^^^^^^^^
+>id : string | undefined
+>   : ^^^^^^^^^^^^^^^^^^
+
+  const isBundled = id?.includes("_bundled");
+>isBundled : boolean | undefined
+>          : ^^^^^^^^^^^^^^^^^^^
+>id?.includes("_bundled") : boolean | undefined
+>                         : ^^^^^^^^^^^^^^^^^^^
+>id?.includes : ((searchString: string, position?: number) => boolean) | undefined
+>             : ^^            ^^      ^^        ^^^      ^^^^^       ^^^^^^^^^^^^^
+>id : string | undefined
+>   : ^^^^^^^^^^^^^^^^^^
+>includes : ((searchString: string, position?: number) => boolean) | undefined
+>         : ^^            ^^      ^^        ^^^      ^^^^^       ^^^^^^^^^^^^^
+>"_bundled" : "_bundled"
+>           : ^^^^^^^^^^
+
+  if (isBundled) {
+>isBundled : boolean | undefined
+>          : ^^^^^^^^^^^^^^^^^^^
+
+    const str: string = id;
+>str : string
+>    : ^^^^^^
+>id : string
+>   : ^^^^^^
+  }
+}
+
+function resolve2(id: string | undefined) {
+>resolve2 : (id: string | undefined) => void
+>         : ^  ^^                  ^^^^^^^^^
+>id : string | undefined
+>   : ^^^^^^^^^^^^^^^^^^
+
+  if (id?.includes("_bundled")) {
+>id?.includes("_bundled") : boolean | undefined
+>                         : ^^^^^^^^^^^^^^^^^^^
+>id?.includes : ((searchString: string, position?: number) => boolean) | undefined
+>             : ^^            ^^      ^^        ^^^      ^^^^^       ^^^^^^^^^^^^^
+>id : string | undefined
+>   : ^^^^^^^^^^^^^^^^^^
+>includes : ((searchString: string, position?: number) => boolean) | undefined
+>         : ^^            ^^      ^^        ^^^      ^^^^^       ^^^^^^^^^^^^^
+>"_bundled" : "_bundled"
+>           : ^^^^^^^^^^
+
+    const str: string = id;
+>str : string
+>    : ^^^^^^
+>id : string
+>   : ^^^^^^
+  }
+}
+
diff --git a/tests/cases/conformance/controlFlow/controlFlowOptionalChain5.ts b/tests/cases/conformance/controlFlow/controlFlowOptionalChain5.ts
new file mode 100644
index 0000000000000..0ebfe9aaa7c9e
--- /dev/null
+++ b/tests/cases/conformance/controlFlow/controlFlowOptionalChain5.ts
@@ -0,0 +1,18 @@
+// @strict: true
+// @lib: esnext
+// @noEmit: true
+
+// https://github.com/microsoft/TypeScript/issues/59145
+
+function resolve1(id: string | undefined) {
+  const isBundled = id?.includes("_bundled");
+  if (isBundled) {
+    const str: string = id;
+  }
+}
+
+function resolve2(id: string | undefined) {
+  if (id?.includes("_bundled")) {
+    const str: string = id;
+  }
+}