diff --git a/libraries/libmdb/midl.c b/libraries/libmdb/midl.c
index 9ee100d..8de61e3 100644
--- a/libraries/libmdb/midl.c
+++ b/libraries/libmdb/midl.c
@@ -232,7 +232,7 @@ mdb_midl_sort( MDB_IDL ids )
 			ids[l+1] = ids[j];
 			ids[j] = a;
 			jstack += 2;
-			if (ir-i+1 >= j-1) {
+			if (ir-i+1 >= j-l) {
 				istack[jstack] = ir;
 				istack[jstack-1] = i;
 				ir = j-1;