diff --git a/packages/babel-types/README.md b/packages/babel-types/README.md
index cfbf35c46014..39ade888924d 100644
--- a/packages/babel-types/README.md
+++ b/packages/babel-types/README.md
@@ -2183,7 +2183,7 @@ Aliases: `TSTypeElement`
 
  - `key`: `Expression` (required)
  - `typeAnnotation`: `TypeAnnotation` (default: `null`)
- - `initializer`: `Expresssion` (default: `null`)
+ - `initializer`: `Expression` (default: `null`)
  - `computed`: `boolean` (default: `null`)
  - `optional`: `boolean` (default: `null`)
  - `readonly`: `boolean` (default: `null`)
diff --git a/packages/babel-types/src/definitions/typescript.js b/packages/babel-types/src/definitions/typescript.js
index e75918dba84d..5bcac559508e 100644
--- a/packages/babel-types/src/definitions/typescript.js
+++ b/packages/babel-types/src/definitions/typescript.js
@@ -115,7 +115,7 @@ defineType("TSPropertySignature", {
     ...namedTypeElementCommon,
     readonly: validateOptional(bool),
     typeAnnotation: validateOptionalType("TypeAnnotation"),
-    initializer: validateOptionalType("Expresssion"),
+    initializer: validateOptionalType("Expression"),
   },
 });