diff --git a/extensions/notebook/src/dialog/configurePython/configurePythonWizard.ts b/extensions/notebook/src/dialog/configurePython/configurePythonWizard.ts
index 7df8efb7af..6688d50c4c 100644
--- a/extensions/notebook/src/dialog/configurePython/configurePythonWizard.ts
+++ b/extensions/notebook/src/dialog/configurePython/configurePythonWizard.ts
@@ -99,6 +99,10 @@ export class ConfigurePythonWizard {
 		});
 
 		this._wizard.registerNavigationValidator(async (info) => {
+			// The pages have not been registered yet
+			if (pages.size === 0) {
+				return false;
+			}
 			let lastPage = pages.get(info.lastPage);
 			let newPage = pages.get(info.newPage);