diff --git a/src/bin/shared/initializeSpa/addSyncExtensionsToPostinstallScript.ts b/src/bin/shared/initializeSpa/addSyncExtensionsToPostinstallScript.ts
index d8963f74..c0a15f5b 100644
--- a/src/bin/shared/initializeSpa/addSyncExtensionsToPostinstallScript.ts
+++ b/src/bin/shared/initializeSpa/addSyncExtensionsToPostinstallScript.ts
@@ -56,7 +56,7 @@ export function addSyncExtensionsToPostinstallScript(params: {
                 continue;
             }
 
-            if (cmd_preexisting.includes(cmd_base)) {
+            if (!cmd_preexisting.includes(cmd_base)) {
                 scripts[scriptName] = generateCmd({ cmd_preexisting });
                 return;
             }