diff --git a/src/engine.c b/src/engine.c
index 40365c4676c6ce8ad2d402b28fdea34ea606b597..73eb3712fb123e2078bcef49a2d91d650445c3ca 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -735,7 +735,7 @@ struct savelink_mapper_data {
       for (int k = 0; k < counts[nodeID * nr_nodes + node]; k++) {             \
         if (parts[k + offset].gpart != NULL) {                                 \
           if (CHECKS)                                                          \
-            if (parts[k].gpart->id_or_neg_offset > 0)                          \
+            if (parts[k + offset].gpart->id_or_neg_offset > 0)                 \
               error("Trying to link a partnerless " #TYPE "!");                \
           parts[k + offset].gpart->id_or_neg_offset = -count;                  \
           count++;                                                             \