diff --git a/src/globcon/mod.ts b/src/globcon/mod.ts
index b9307f8..eb18ce0 100644
--- a/src/globcon/mod.ts
+++ b/src/globcon/mod.ts
@@ -43,9 +43,9 @@ export function checkHttpUrl(url: string) {
 }
 
 export function checkRedundantConfig(conf: libsqlConfig) {
-    if (conf.encryptionKey) conserror("'encryptionKey' config unsupported.");
-    if (conf.syncUrl) conserror("'syncUrl' config unsupported because 'url' is the remote url. (embedded replicas unsupported)");
-    if (conf.syncInterval) conserror("'syncInterval' config unsupported because nothing to sync. (embedded replicas unsupported)");
-    if (conf.tls) conserror("'tls' config unsupported. Change url scheme to 'http' for no tls and 'https' for tls.");
-    if (conf.concurrency) conserror("'concurrency' config unsupported. You may use a custom fetch to specify concurrency.");
+    if (conf.encryptionKey !== undefined) conserror("'encryptionKey' config unsupported.");
+    if (conf.syncUrl !== undefined) conserror("'syncUrl' config unsupported because 'url' is the remote url. (embedded replicas unsupported)");
+    if (conf.syncInterval !== undefined) conserror("'syncInterval' config unsupported because nothing to sync. (embedded replicas unsupported)");
+    if (conf.tls !== undefined) conserror("'tls' config unsupported. Change url scheme to 'http' for no tls and 'https' for tls.");
+    if (conf.concurrency !== undefined) conserror("'concurrency' config unsupported. You may use a custom fetch to specify concurrency.");
 }
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