diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index b448910799401..766aac9e595b8 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -5201,6 +5201,7 @@ namespace Parser {
                         switch (fourth) {
                             case SyntaxKind.EqualsToken:
                             case SyntaxKind.GreaterThanToken:
+                            case SyntaxKind.SlashToken:
                                 return false;
                             default:
                                 return true;
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 57c7bf9aa8329..dd340dbfe8d22 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -9079,7 +9079,7 @@ export function rangeOfNode(node: Node): TextRange {
 export function rangeOfTypeParameters(sourceFile: SourceFile, typeParameters: NodeArray<TypeParameterDeclaration>): TextRange {
     // Include the `<>`
     const pos = typeParameters.pos - 1;
-    const end = skipTrivia(sourceFile.text, typeParameters.end) + 1;
+    const end = Math.min(sourceFile.text.length, skipTrivia(sourceFile.text, typeParameters.end) + 1);
     return { pos, end };
 }
 
diff --git a/tests/baselines/reference/parseJsxExtends1.js b/tests/baselines/reference/parseJsxExtends1.js
new file mode 100644
index 0000000000000..893228c3f6855
--- /dev/null
+++ b/tests/baselines/reference/parseJsxExtends1.js
@@ -0,0 +1,18 @@
+//// [index.tsx]
+declare const React: any;
+
+export function Foo() {
+    // No error; "const" is lowercase and therefore intrinsic.
+    return <const T extends/>
+}
+
+
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.Foo = void 0;
+function Foo() {
+    // No error; "const" is lowercase and therefore intrinsic.
+    return React.createElement("const", { T: true, extends: true });
+}
+exports.Foo = Foo;
diff --git a/tests/baselines/reference/parseJsxExtends1.symbols b/tests/baselines/reference/parseJsxExtends1.symbols
new file mode 100644
index 0000000000000..7b4981044b6b3
--- /dev/null
+++ b/tests/baselines/reference/parseJsxExtends1.symbols
@@ -0,0 +1,13 @@
+=== tests/cases/compiler/index.tsx ===
+declare const React: any;
+>React : Symbol(React, Decl(index.tsx, 0, 13))
+
+export function Foo() {
+>Foo : Symbol(Foo, Decl(index.tsx, 0, 25))
+
+    // No error; "const" is lowercase and therefore intrinsic.
+    return <const T extends/>
+>T : Symbol(T, Decl(index.tsx, 4, 17))
+>extends : Symbol(extends, Decl(index.tsx, 4, 19))
+}
+
diff --git a/tests/baselines/reference/parseJsxExtends1.types b/tests/baselines/reference/parseJsxExtends1.types
new file mode 100644
index 0000000000000..5e605aa1e2515
--- /dev/null
+++ b/tests/baselines/reference/parseJsxExtends1.types
@@ -0,0 +1,15 @@
+=== tests/cases/compiler/index.tsx ===
+declare const React: any;
+>React : any
+
+export function Foo() {
+>Foo : () => any
+
+    // No error; "const" is lowercase and therefore intrinsic.
+    return <const T extends/>
+><const T extends/> : error
+>const : any
+>T : true
+>extends : true
+}
+
diff --git a/tests/baselines/reference/parseJsxExtends2.errors.txt b/tests/baselines/reference/parseJsxExtends2.errors.txt
new file mode 100644
index 0000000000000..d482f0277abe5
--- /dev/null
+++ b/tests/baselines/reference/parseJsxExtends2.errors.txt
@@ -0,0 +1,13 @@
+tests/cases/compiler/index.tsx(5,13): error TS2304: Cannot find name 'T'.
+
+
+==== tests/cases/compiler/index.tsx (1 errors) ====
+    declare const React: any;
+    
+    export function Foo() {
+        // Error: T is not declared.
+        return <T extends/>
+                ~
+!!! error TS2304: Cannot find name 'T'.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/parseJsxExtends2.js b/tests/baselines/reference/parseJsxExtends2.js
new file mode 100644
index 0000000000000..7a09169319c6c
--- /dev/null
+++ b/tests/baselines/reference/parseJsxExtends2.js
@@ -0,0 +1,18 @@
+//// [index.tsx]
+declare const React: any;
+
+export function Foo() {
+    // Error: T is not declared.
+    return <T extends/>
+}
+
+
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.Foo = void 0;
+function Foo() {
+    // Error: T is not declared.
+    return React.createElement(T, { extends: true });
+}
+exports.Foo = Foo;
diff --git a/tests/baselines/reference/parseJsxExtends2.symbols b/tests/baselines/reference/parseJsxExtends2.symbols
new file mode 100644
index 0000000000000..b222fb8d35cc8
--- /dev/null
+++ b/tests/baselines/reference/parseJsxExtends2.symbols
@@ -0,0 +1,12 @@
+=== tests/cases/compiler/index.tsx ===
+declare const React: any;
+>React : Symbol(React, Decl(index.tsx, 0, 13))
+
+export function Foo() {
+>Foo : Symbol(Foo, Decl(index.tsx, 0, 25))
+
+    // Error: T is not declared.
+    return <T extends/>
+>extends : Symbol(extends, Decl(index.tsx, 4, 13))
+}
+
diff --git a/tests/baselines/reference/parseJsxExtends2.types b/tests/baselines/reference/parseJsxExtends2.types
new file mode 100644
index 0000000000000..b9dcb4f5958d0
--- /dev/null
+++ b/tests/baselines/reference/parseJsxExtends2.types
@@ -0,0 +1,14 @@
+=== tests/cases/compiler/index.tsx ===
+declare const React: any;
+>React : any
+
+export function Foo() {
+>Foo : () => any
+
+    // Error: T is not declared.
+    return <T extends/>
+><T extends/> : any
+>T : any
+>extends : true
+}
+
diff --git a/tests/cases/compiler/parseJsxExtends1.ts b/tests/cases/compiler/parseJsxExtends1.ts
new file mode 100644
index 0000000000000..7dbf396d6efc8
--- /dev/null
+++ b/tests/cases/compiler/parseJsxExtends1.ts
@@ -0,0 +1,9 @@
+// @jsx: react
+// @filename: index.tsx
+
+declare const React: any;
+
+export function Foo() {
+    // No error; "const" is lowercase and therefore intrinsic.
+    return <const T extends/>
+}
diff --git a/tests/cases/compiler/parseJsxExtends2.ts b/tests/cases/compiler/parseJsxExtends2.ts
new file mode 100644
index 0000000000000..10309c2b6dc53
--- /dev/null
+++ b/tests/cases/compiler/parseJsxExtends2.ts
@@ -0,0 +1,9 @@
+// @jsx: react
+// @filename: index.tsx
+
+declare const React: any;
+
+export function Foo() {
+    // Error: T is not declared.
+    return <T extends/>
+}
diff --git a/tests/cases/fourslash/jsxElementExtendsNoCrash1.ts b/tests/cases/fourslash/jsxElementExtendsNoCrash1.ts
new file mode 100644
index 0000000000000..6959cc9ce40e8
--- /dev/null
+++ b/tests/cases/fourslash/jsxElementExtendsNoCrash1.ts
@@ -0,0 +1,6 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: index.tsx
+//// <const T extends/>
+
+verify.getSuggestionDiagnostics([]);
diff --git a/tests/cases/fourslash/jsxElementExtendsNoCrash2.ts b/tests/cases/fourslash/jsxElementExtendsNoCrash2.ts
new file mode 100644
index 0000000000000..4c42f85626517
--- /dev/null
+++ b/tests/cases/fourslash/jsxElementExtendsNoCrash2.ts
@@ -0,0 +1,6 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: index.tsx
+//// <T extends/>
+
+verify.getSuggestionDiagnostics([]);
diff --git a/tests/cases/fourslash/jsxElementExtendsNoCrash3.ts b/tests/cases/fourslash/jsxElementExtendsNoCrash3.ts
new file mode 100644
index 0000000000000..c4b85cb423046
--- /dev/null
+++ b/tests/cases/fourslash/jsxElementExtendsNoCrash3.ts
@@ -0,0 +1,6 @@
+/// <reference path="fourslash.ts" />
+
+// @filename: index.tsx
+//// <T extends /=>
+
+verify.getSuggestionDiagnostics([]);