diff --git a/persistent-data/space-maps/recursive.cc b/persistent-data/space-maps/recursive.cc
index 634c530..46d6ed5 100644
--- a/persistent-data/space-maps/recursive.cc
+++ b/persistent-data/space-maps/recursive.cc
@@ -216,7 +216,10 @@ namespace {
 
 				switch (op.op_) {
 				case INC:
-					sm_->inc(b, op.rc_);
+					if (op.rc_ > 0)
+						sm_->inc(b, op.rc_);
+					else if (op.rc_ < 0)
+						sm_->dec(b, -op.rc_);
 					break;
 
 				case SET: