diff --git a/api/ReadableStreamDefaultReader.json b/api/ReadableStreamDefaultReader.json
index 5ec6fcf3e16ac3..15a17a714277d2 100644
--- a/api/ReadableStreamDefaultReader.json
+++ b/api/ReadableStreamDefaultReader.json
@@ -6,7 +6,7 @@
         "spec_url": "https://streams.spec.whatwg.org/#default-reader-class",
         "support": {
           "chrome": {
-            "version_added": "78"
+            "version_added": "43"
           },
           "chrome_android": "mirror",
           "deno": [
@@ -106,7 +106,7 @@
           "spec_url": "https://streams.spec.whatwg.org/#ref-for-generic-reader-cancel②",
           "support": {
             "chrome": {
-              "version_added": "78"
+              "version_added": "43"
             },
             "chrome_android": "mirror",
             "deno": {
@@ -147,7 +147,7 @@
           "spec_url": "https://streams.spec.whatwg.org/#ref-for-generic-reader-closed②",
           "support": {
             "chrome": {
-              "version_added": "78"
+              "version_added": "43"
             },
             "chrome_android": "mirror",
             "deno": {
@@ -188,7 +188,7 @@
           "spec_url": "https://streams.spec.whatwg.org/#ref-for-default-reader-read①",
           "support": {
             "chrome": {
-              "version_added": "78"
+              "version_added": "43"
             },
             "chrome_android": "mirror",
             "deno": {
@@ -229,7 +229,7 @@
           "spec_url": "https://streams.spec.whatwg.org/#ref-for-default-reader-release-lock②",
           "support": {
             "chrome": {
-              "version_added": "78"
+              "version_added": "43"
             },
             "chrome_android": "mirror",
             "deno": {