diff --git a/src/validation/ContentDataValidator.ts b/src/validation/ContentDataValidator.ts
index c17ce861..eadfa128 100644
--- a/src/validation/ContentDataValidator.ts
+++ b/src/validation/ContentDataValidator.ts
@@ -166,7 +166,7 @@ export class ContentDataValidator {
     );
     const derivedResult = derivedContext.getResult();
 
-    // All all extensions that have been found in the content
+    // Add all extensions that have been found in the content
     // to the current context. They also have to appear in
     // the 'extensionsUsed' of the containing tileset.
     const derivedExtensionsFound = derivedContext.getExtensionsFound();
diff --git a/src/validation/TilesetPackageValidator.ts b/src/validation/TilesetPackageValidator.ts
index bf2f8c5f..cbdb4aa1 100644
--- a/src/validation/TilesetPackageValidator.ts
+++ b/src/validation/TilesetPackageValidator.ts
@@ -239,7 +239,7 @@ export class TilesetPackageValidator implements Validator<string> {
     );
     const derivedResult = derivedContext.getResult();
 
-    // All all extensions that have been found in the tileset
+    // Add all extensions that have been found in the tileset
     // to the current context. They also have to appear in
     // the 'extensionsUsed' of the containing tileset.
     const derivedExtensionsFound = derivedContext.getExtensionsFound();