diff --git a/docs/adding-new-languages.md b/docs/adding-new-languages.md
index 6b331ad654..9d6bc5e0f1 100644
--- a/docs/adding-new-languages.md
+++ b/docs/adding-new-languages.md
@@ -7,7 +7,7 @@ Please note that this list of steps reflects the state of Semantic as is, not wh
 ## The procedure
 
 1. **Find or write a [tree-sitter](https://tree-sitter.github.io) parser for your language.** The tree-sitter [organization page](https://github.com/tree-sitter) has a number of parsers beyond those we currently support in Semantic; look there first to make sure you're not duplicating work. The tree-sitter [documentation on creating parsers](http://tree-sitter.github.io/tree-sitter/creating-parsers) provides an exhaustive look at the process of developing and debugging tree-sitter parsers. Though we do not support grammars written with other toolkits such as [ANTLR](https://www.antlr.org), translating an ANTLR or other BNF-style grammar into a tree-sitter grammar is usually straightforward.
-2. **Create a Haskell library providing an interface to that C source.** The [`haskell-tree-sitter`](https://github.com/tree-sitter/haskell-tree-sitter/tree/master/languages) repository provides a Cabal package for each supported language. You can find an example of a pull request to add such a package here. Each package needs to provide two API surfaces:
+2. **Create a Haskell library providing an interface to that C source.** The [`haskell-tree-sitter`](https://github.com/tree-sitter/haskell-tree-sitter) repository provides a Cabal package for each supported language. You can find an example of a pull request to add such a package here. Each package needs to provide two API surfaces:
    * a bridged (via the FFI) reference to the toplevel parser in the generated file ([example](https://github.com/tree-sitter/haskell-tree-sitter/blob/master/tree-sitter-json/internal/TreeSitter/JSON/Internal.hs))
    * symbol datatypes for each syntax node in the parser, generated with the `mkSymbolDatatype` Template Haskell splice ([example](https://github.com/tree-sitter/haskell-tree-sitter/blob/master/tree-sitter-json/TreeSitter/JSON.hs))
 3. **Identify the new syntax nodes required to represent your language.** While we provide an extensive library of reusable AST nodes for [literals](https://github.com/github/semantic/blob/master/src/Data/Syntax/Literal.hs), [expressions](https://github.com/github/semantic/blob/master/src/Data/Syntax/Expression.hs), [statements](https://github.com/github/semantic/blob/master/src/Data/Syntax/Statement.hs), and [types](https://github.com/github/semantic/blob/master/src/Data/Syntax/Type.hs), most languages will require some syntax nodes not found in other languages. You'll need to create a new module providing those data types, and those data types must be written as an open union: [here](https://github.com/github/semantic/commits/master/src/Language/Ruby/Syntax.hs?author=charliesome) is an example for Ruby's syntactic details.
diff --git a/src/Language/TSX/Assignment.hs b/src/Language/TSX/Assignment.hs
index 839f7aeca1..2f79a0bae7 100644
--- a/src/Language/TSX/Assignment.hs
+++ b/src/Language/TSX/Assignment.hs
@@ -429,7 +429,7 @@ jsxAttribute' :: Assignment Term
 jsxAttribute' = jsxAttribute <|> jsxExpression'
 
 jsxOpeningElement' :: Assignment Term
-jsxOpeningElement' = makeTerm <$> symbol Grammar.JsxOpeningElement <*> children (TSX.Syntax.JsxOpeningElement <$> term jsxElementName <*> manyTerm jsxAttribute')
+jsxOpeningElement' = makeTerm <$> symbol Grammar.JsxOpeningElement <*> children (TSX.Syntax.JsxOpeningElement <$> term jsxElementName <*> term (typeArguments' <|> emptyTerm) <*> manyTerm jsxAttribute')
 
 jsxElementName :: Assignment Term
 jsxElementName = choice [ identifier, nestedIdentifier, jsxNamespaceName ]
diff --git a/src/Language/TSX/Syntax/JSX.hs b/src/Language/TSX/Syntax/JSX.hs
index 9430e67435..113b0375a9 100644
--- a/src/Language/TSX/Syntax/JSX.hs
+++ b/src/Language/TSX/Syntax/JSX.hs
@@ -28,7 +28,7 @@ newtype JsxExpression a = JsxExpression { jsxExpression :: a }
 
 instance Evaluatable JsxExpression
 
-data JsxOpeningElement a = JsxOpeningElement { jsxOpeningElementIdentifier :: !a,  jsxAttributes :: ![a] }
+data JsxOpeningElement a = JsxOpeningElement { jsxOpeningElementIdentifier :: !a, jsxOpeningElementTypeArguments :: a, jsxAttributes :: ![a] }
   deriving (Declarations1, Diffable, Eq, Foldable, FreeVariables1, Functor, Generic1, Hashable1, NFData1, Ord, Show, ToJSONFields1, Traversable)
   deriving (Eq1, Show1, Ord1) via Generically JsxOpeningElement
 
diff --git a/src/Parsing/Parser.hs b/src/Parsing/Parser.hs
index c4bca8f5a5..09c37e63e3 100644
--- a/src/Parsing/Parser.hs
+++ b/src/Parsing/Parser.hs
@@ -191,9 +191,13 @@ someASTParser :: Language -> Maybe SomeASTParser
 someASTParser Go         = Just (SomeASTParser (ASTParser tree_sitter_go :: Parser (AST [] Go.Grammar)))
 someASTParser Haskell    = Just (SomeASTParser (ASTParser tree_sitter_haskell :: Parser (AST [] Haskell.Grammar)))
 someASTParser Java       = Just (SomeASTParser (ASTParser tree_sitter_java :: Parser (AST [] Java.Grammar)))
-someASTParser JavaScript = Just (SomeASTParser (ASTParser tree_sitter_typescript :: Parser (AST [] TypeScript.Grammar)))
 someASTParser JSON       = Just (SomeASTParser (ASTParser tree_sitter_json :: Parser (AST [] JSON.Grammar)))
-someASTParser JSX        = Just (SomeASTParser (ASTParser tree_sitter_typescript :: Parser (AST [] TypeScript.Grammar)))
+
+-- Use the TSX parser for `.js` and `.jsx` files in case they use Flow type-annotation syntax.
+-- The TSX and Flow syntaxes are the same, whereas the normal TypeScript syntax is different.
+someASTParser JavaScript = Just (SomeASTParser (ASTParser tree_sitter_tsx :: Parser (AST [] TSX.Grammar)))
+someASTParser JSX        = Just (SomeASTParser (ASTParser tree_sitter_tsx :: Parser (AST [] TSX.Grammar)))
+
 someASTParser Python     = Just (SomeASTParser (ASTParser tree_sitter_python :: Parser (AST [] Python.Grammar)))
 someASTParser Ruby       = Just (SomeASTParser (ASTParser tree_sitter_ruby :: Parser (AST [] Ruby.Grammar)))
 someASTParser TypeScript = Just (SomeASTParser (ASTParser tree_sitter_typescript :: Parser (AST [] TypeScript.Grammar)))
diff --git a/test/fixtures/javascript/corpus/jsx.A.js b/test/fixtures/javascript/corpus/jsx.A.js
new file mode 100644
index 0000000000..5b4c905660
--- /dev/null
+++ b/test/fixtures/javascript/corpus/jsx.A.js
@@ -0,0 +1,5 @@
+function Something() {
+  return <div>
+    <Foo>hello</Foo>
+  </div>;
+}
diff --git a/test/fixtures/javascript/corpus/jsx.B.js b/test/fixtures/javascript/corpus/jsx.B.js
new file mode 100644
index 0000000000..237faaca55
--- /dev/null
+++ b/test/fixtures/javascript/corpus/jsx.B.js
@@ -0,0 +1,5 @@
+function Something() {
+  return <div>
+    <Foo<T>>goodbye</Foo>
+  </div>;
+}
diff --git a/test/fixtures/javascript/corpus/jsx.diffA-B.txt b/test/fixtures/javascript/corpus/jsx.diffA-B.txt
new file mode 100644
index 0000000000..9286a8dc28
--- /dev/null
+++ b/test/fixtures/javascript/corpus/jsx.diffA-B.txt
@@ -0,0 +1,25 @@
+(Statements
+  (Function
+    (Empty)
+    (Empty)
+    (Identifier)
+    (StatementBlock
+      (Return
+        (JsxElement
+          (JsxOpeningElement
+            (Identifier)
+            (Empty))
+          (JsxText)
+          (JsxElement
+            (JsxOpeningElement
+              (Identifier)
+            { (Empty)
+            ->(TypeArguments
+              {+(TypeIdentifier)+}) })
+          { (JsxText)
+          ->(JsxText) }
+            (JsxClosingElement
+              (Identifier)))
+          (JsxText)
+          (JsxClosingElement
+            (Identifier)))))))
diff --git a/test/fixtures/javascript/corpus/jsx.diffB-A.txt b/test/fixtures/javascript/corpus/jsx.diffB-A.txt
new file mode 100644
index 0000000000..708286acdb
--- /dev/null
+++ b/test/fixtures/javascript/corpus/jsx.diffB-A.txt
@@ -0,0 +1,25 @@
+(Statements
+  (Function
+    (Empty)
+    (Empty)
+    (Identifier)
+    (StatementBlock
+      (Return
+        (JsxElement
+          (JsxOpeningElement
+            (Identifier)
+            (Empty))
+          (JsxText)
+          (JsxElement
+            (JsxOpeningElement
+              (Identifier)
+            { (TypeArguments
+              {-(TypeIdentifier)-})
+            ->(Empty) })
+          { (JsxText)
+          ->(JsxText) }
+            (JsxClosingElement
+              (Identifier)))
+          (JsxText)
+          (JsxClosingElement
+            (Identifier)))))))
diff --git a/test/fixtures/javascript/corpus/jsx.parseA.txt b/test/fixtures/javascript/corpus/jsx.parseA.txt
new file mode 100644
index 0000000000..c42723ce3d
--- /dev/null
+++ b/test/fixtures/javascript/corpus/jsx.parseA.txt
@@ -0,0 +1,22 @@
+(Statements
+  (Function
+    (Empty)
+    (Empty)
+    (Identifier)
+    (StatementBlock
+      (Return
+        (JsxElement
+          (JsxOpeningElement
+            (Identifier)
+            (Empty))
+          (JsxText)
+          (JsxElement
+            (JsxOpeningElement
+              (Identifier)
+              (Empty))
+            (JsxText)
+            (JsxClosingElement
+              (Identifier)))
+          (JsxText)
+          (JsxClosingElement
+            (Identifier)))))))
diff --git a/test/fixtures/javascript/corpus/jsx.parseB.txt b/test/fixtures/javascript/corpus/jsx.parseB.txt
new file mode 100644
index 0000000000..4916b0be6b
--- /dev/null
+++ b/test/fixtures/javascript/corpus/jsx.parseB.txt
@@ -0,0 +1,23 @@
+(Statements
+  (Function
+    (Empty)
+    (Empty)
+    (Identifier)
+    (StatementBlock
+      (Return
+        (JsxElement
+          (JsxOpeningElement
+            (Identifier)
+            (Empty))
+          (JsxText)
+          (JsxElement
+            (JsxOpeningElement
+              (Identifier)
+              (TypeArguments
+                (TypeIdentifier)))
+            (JsxText)
+            (JsxClosingElement
+              (Identifier)))
+          (JsxText)
+          (JsxClosingElement
+            (Identifier)))))))
diff --git a/test/fixtures/tsx/corpus/jsx-elements.diffA-B.txt b/test/fixtures/tsx/corpus/jsx-elements.diffA-B.txt
index 9e330c8d5c..04d7fa6870 100644
--- a/test/fixtures/tsx/corpus/jsx-elements.diffA-B.txt
+++ b/test/fixtures/tsx/corpus/jsx-elements.diffA-B.txt
@@ -6,6 +6,7 @@
       (JsxElement
         (JsxOpeningElement
           (Identifier)
+          (Empty)
         {+(JsxAttribute
           {+(Identifier)+}
           {+(JsxExpression
@@ -31,7 +32,8 @@
       {-(JsxOpeningElement
         {-(NestedIdentifier
           {-(Identifier)-}
-          {-(Identifier)-})-})-}
+          {-(Identifier)-})-}
+        {-(Empty)-})-}
       {-(JsxClosingElement
         {-(NestedIdentifier
           {-(Identifier)-}
diff --git a/test/fixtures/tsx/corpus/jsx-elements.diffB-A.txt b/test/fixtures/tsx/corpus/jsx-elements.diffB-A.txt
index 6f4ba9f23e..bb6402bef0 100644
--- a/test/fixtures/tsx/corpus/jsx-elements.diffB-A.txt
+++ b/test/fixtures/tsx/corpus/jsx-elements.diffB-A.txt
@@ -6,6 +6,7 @@
       (JsxElement
         (JsxOpeningElement
           (Identifier)
+          (Empty)
         {+(JsxExpression
           {+(Call
             {+(Identifier)+}
@@ -31,7 +32,8 @@
       {+(JsxOpeningElement
         {+(NestedIdentifier
           {+(Identifier)+}
-          {+(Identifier)+})+})+}
+          {+(Identifier)+})+}
+        {+(Empty)+})+}
       {+(JsxClosingElement
         {+(NestedIdentifier
           {+(Identifier)+}
diff --git a/test/fixtures/tsx/corpus/jsx-elements.parseA.txt b/test/fixtures/tsx/corpus/jsx-elements.parseA.txt
index 85d98a0356..579b272fe3 100644
--- a/test/fixtures/tsx/corpus/jsx-elements.parseA.txt
+++ b/test/fixtures/tsx/corpus/jsx-elements.parseA.txt
@@ -6,6 +6,7 @@
       (JsxElement
         (JsxOpeningElement
           (Identifier)
+          (Empty)
           (JsxExpression
             (Call
               (Identifier)
@@ -25,7 +26,8 @@
         (JsxOpeningElement
           (NestedIdentifier
             (Identifier)
-            (Identifier)))
+            (Identifier))
+          (Empty))
         (JsxClosingElement
           (NestedIdentifier
             (Identifier)
diff --git a/test/fixtures/tsx/corpus/jsx-elements.parseB.txt b/test/fixtures/tsx/corpus/jsx-elements.parseB.txt
index 32aee1e269..6e1a3a3ac9 100644
--- a/test/fixtures/tsx/corpus/jsx-elements.parseB.txt
+++ b/test/fixtures/tsx/corpus/jsx-elements.parseB.txt
@@ -6,6 +6,7 @@
       (JsxElement
         (JsxOpeningElement
           (Identifier)
+          (Empty)
           (JsxAttribute
             (Identifier)
             (JsxExpression