diff --git a/extensions/github-authentication/src/github.ts b/extensions/github-authentication/src/github.ts
index ed584c65f8b..231c793e6a4 100644
--- a/extensions/github-authentication/src/github.ts
+++ b/extensions/github-authentication/src/github.ts
@@ -18,7 +18,9 @@ interface SessionData {
 	account?: {
 		label?: string;
 		displayName?: string;
-		id: string;
+		// Unfortunately, for some time the id was a number, so we need to support both.
+		// This can be removed once we are confident that all users have migrated to the new id.
+		id: string | number;
 	};
 	scopes: string[];
 	accessToken: string;
@@ -239,9 +241,14 @@ export class GitHubAuthenticationProvider implements vscode.AuthenticationProvid
 			return [];
 		}
 
+		// Unfortunately, we were using a number secretly for the account id for some time... this is due to a bad `any`.
+		// AuthenticationSession's account id is a string, so we need to detect when there is a number accountId and re-store
+		// the sessions to migrate away from the bad number usage.
+		// TODO@TylerLeonhardt: Remove this after we are confident that all users have migrated to the new id.
+		let seenNumberAccountId: boolean = false;
 		// TODO: eventually remove this Set because we should only have one session per set of scopes.
 		const scopesSeen = new Set<string>();
-		const sessionPromises = sessionData.map(async (session: SessionData) => {
+		const sessionPromises = sessionData.map(async (session: SessionData): Promise<vscode.AuthenticationSession | undefined> => {
 			// For GitHub scope list, order doesn't matter so we immediately sort the scopes
 			const scopesStr = [...session.scopes].sort().join(' ');
 			if (!this._supportsMultipleAccounts && scopesSeen.has(scopesStr)) {
@@ -262,13 +269,23 @@ export class GitHubAuthenticationProvider implements vscode.AuthenticationProvid
 
 			this._logger.trace(`Read the following session from the keychain with the following scopes: ${scopesStr}`);
 			scopesSeen.add(scopesStr);
+
+			let accountId: string;
+			if (session.account?.id) {
+				if (typeof session.account.id === 'number') {
+					seenNumberAccountId = true;
+				}
+				accountId = `${session.account.id}`;
+			} else {
+				accountId = userInfo?.id ?? '<unknown>';
+			}
 			return {
 				id: session.id,
 				account: {
 					label: session.account
 						? session.account.label ?? session.account.displayName ?? '<unknown>'
 						: userInfo?.accountName ?? '<unknown>',
-					id: session.account?.id ?? userInfo?.id ?? '<unknown>'
+					id: accountId
 				},
 				// we set this to session.scopes to maintain the original order of the scopes requested
 				// by the extension that called getSession()
@@ -283,7 +300,7 @@ export class GitHubAuthenticationProvider implements vscode.AuthenticationProvid
 			.filter(<T>(p?: T): p is T => Boolean(p));
 
 		this._logger.info(`Got ${verifiedSessions.length} verified sessions.`);
-		if (verifiedSessions.length !== sessionData.length) {
+		if (seenNumberAccountId || verifiedSessions.length !== sessionData.length) {
 			await this.storeSessions(verifiedSessions);
 		}
 
diff --git a/extensions/github-authentication/src/githubServer.ts b/extensions/github-authentication/src/githubServer.ts
index c9f0a8c07d5..a9f94ccf65d 100644
--- a/extensions/github-authentication/src/githubServer.ts
+++ b/extensions/github-authentication/src/githubServer.ts
@@ -228,9 +228,9 @@ export class GitHubServer implements IGitHubServer {
 
 		if (result.ok) {
 			try {
-				const json = await result.json();
+				const json = await result.json() as { id: number; login: string };
 				this._logger.info('Got account info!');
-				return { id: json.id, accountName: json.login };
+				return { id: `${json.id}`, accountName: json.login };
 			} catch (e) {
 				this._logger.error(`Unexpected error parsing response from GitHub: ${e.message ?? e}`);
 				throw e;