diff --git a/packages/cli/src/utils/sandboxUtils.ts b/packages/cli/src/utils/sandboxUtils.ts
index 2f5871a0c12..48cfb30f000 100644
--- a/packages/cli/src/utils/sandboxUtils.ts
+++ b/packages/cli/src/utils/sandboxUtils.ts
@@ -134,12 +134,14 @@ export function entrypoint(workdir: string, cliArgs: string[]): string[] {
   );
 
   const quotedCliArgs = cliArgs.slice(2).map((arg) => quote([arg]));
+  const isDebugMode =
+    process.env['DEBUG'] === 'true' || process.env['DEBUG'] === '1';
   const cliCmd =
     process.env['NODE_ENV'] === 'development'
-      ? process.env['DEBUG']
+      ? isDebugMode
         ? 'npm run debug --'
         : 'npm rebuild && npm run start --'
-      : process.env['DEBUG']
+      : isDebugMode
         ? `node --inspect-brk=0.0.0.0:${process.env['DEBUG_PORT'] || '9229'} $(which gemini)`
         : 'gemini';
 
diff --git a/scripts/start.js b/scripts/start.js
index 9898d0be30f..cb71ec9c495 100644
--- a/scripts/start.js
+++ b/scripts/start.js
@@ -46,7 +46,9 @@ try {
 // if debugging is enabled and sandboxing is disabled, use --inspect-brk flag
 // note with sandboxing this flag is passed to the binary inside the sandbox
 // inside sandbox SANDBOX should be set and sandbox_command.js should fail
-if (process.env.DEBUG && !sandboxCommand) {
+const isInDebugMode = process.env.DEBUG === '1' || process.env.DEBUG === 'true';
+
+if (isInDebugMode && !sandboxCommand) {
   if (process.env.SANDBOX) {
     const port = process.env.DEBUG_PORT || '9229';
     nodeArgs.push(`--inspect-brk=0.0.0.0:${port}`);
@@ -64,7 +66,7 @@ const env = {
   DEV: 'true',
 };
 
-if (process.env.DEBUG) {
+if (isInDebugMode) {
   // If this is not set, the debugger will pause on the outer process rather
   // than the relaunched process making it harder to debug.
   env.GEMINI_CLI_NO_RELAUNCH = 'true';