diff --git a/server/claude-sdk.js b/server/claude-sdk.js
index c934f595..7239f81a 100644
--- a/server/claude-sdk.js
+++ b/server/claude-sdk.js
@@ -153,9 +153,11 @@ function mapCliOptionsToSDK(options = {}) {
   // Since SDK 0.2.113, options.env replaces process.env instead of overlaying it.
   sdkOptions.env = { ...process.env };
 
-  if (process.env.CLAUDE_CLI_PATH) {
-    sdkOptions.pathToClaudeCodeExecutable = process.env.CLAUDE_CLI_PATH;
-  }
+  // Use CLAUDE_CLI_PATH if explicitly set, otherwise fall back to 'claude' on PATH.
+  // The SDK 0.2.113+ looks for a bundled native binary optional dep by default;
+  // this fallback ensures users who installed via the official installer still work
+  // even when npm prune --production has removed those optional deps.
+  sdkOptions.pathToClaudeCodeExecutable = process.env.CLAUDE_CLI_PATH || 'claude';
 
   // Map working directory
   if (cwd) {