diff --git a/aosp/update_attempter_android.cc b/aosp/update_attempter_android.cc
index 909ce59..857685f 100644
--- a/aosp/update_attempter_android.cc
+++ b/aosp/update_attempter_android.cc
@@ -391,11 +391,11 @@
     auto entries =
         android::base::Split(headers[kPayloadPropertyHTTPExtras], " ");
     for (auto& entry : entries) {
-      auto parts = android::base::Split(entry, ":");
+      auto parts = android::base::Split(entry, ";");
       if (parts.size() != 2) {
         LOG(ERROR)
             << "HTTP headers are not in expected format. "
-               "headers[kPayloadPropertyHTTPExtras] = key1:val1 key2:val2";
+               "headers[kPayloadPropertyHTTPExtras] = key1;val1 key2;val2";
         continue;
       }
       fetcher->SetHeader(parts[0], parts[1]);
diff --git a/common/constants.h b/common/constants.h
index 6b1bf6b..dcd181f 100644
--- a/common/constants.h
+++ b/common/constants.h
@@ -163,7 +163,7 @@
 static constexpr const auto& kPayloadPropertyMetadataHash = "METADATA_HASH";
 // The Authorization: HTTP header to be sent when downloading the payload.
 static constexpr const auto& kPayloadPropertyAuthorization = "AUTHORIZATION";
-// HTTP headers extra entries in the format of key1:val1 key2:val2 key3:val3
+// HTTP headers extra entries in the format of key1;val1 key2;val2 key3;val3
 static constexpr const auto& kPayloadPropertyHTTPExtras = "HTTP_EXTRAS";
 // The User-Agent HTTP header to be sent when downloading the payload.
 static constexpr const auto& kPayloadPropertyUserAgent = "USER_AGENT";