diff --git a/src/business/business-core/gncInvoice.c b/src/business/business-core/gncInvoice.c
index 00644101fe..0ba9849423 100644
--- a/src/business/business-core/gncInvoice.c
+++ b/src/business/business-core/gncInvoice.c
@@ -496,7 +496,7 @@ GncInvoice * gncInvoiceGetInvoiceFromTxn (Transaction *txn)
   kvp_frame *kvp;
   kvp_value *value;
   GUID *guid;
-  GNCBook *book;		/* XXX: FIXME */
+  GNCBook *book = NULL;		/* XXX: FIXME */
 
   if (!txn) return NULL;