Index: libcfa/src/concurrency/kernel/cluster.cfa
===================================================================
--- libcfa/src/concurrency/kernel/cluster.cfa	(revision 4479890a8b920bd26343ba78b81c5b6c26ae3ccf)
+++ libcfa/src/concurrency/kernel/cluster.cfa	(revision 1a567d0b9a1631f52b82268eb951631dcccf030a)
@@ -260,8 +260,10 @@
 		it->rdq.id = valrq;
 		it->rdq.target = MAX;
-		it->io.ctx->cq.id = valio;
-		it->io.target = MAX;
 		valrq += __shard_factor.readyq;
-		valio += __shard_factor.io;
+		#if defined(CFA_HAVE_LINUX_IO_URING_H)
+			it->io.ctx->cq.id = valio;
+			it->io.target = MAX;
+			valio += __shard_factor.io;
+		#endif
 		it = &(*it)`next;
 	}
@@ -275,18 +277,22 @@
 }
 
-static void assign_io($io_context ** data, size_t count, dlist(processor) & list) {
-	processor * it = &list`first;
-	while(it) {
-		/* paranoid */ verifyf( it, "Unexpected null iterator\n");
-		/* paranoid */ verifyf( it->io.ctx->cq.id < count, "Processor %p has id %u above count %zu\n", it, it->rdq.id, count);
-		data[it->io.ctx->cq.id] = it->io.ctx;
-		it = &(*it)`next;
-	}
-}
-
-static void reassign_cltr_io(struct cluster * cltr) {
-	assign_io(cltr->sched.io.data, cltr->sched.io.count, cltr->procs.actives);
-	assign_io(cltr->sched.io.data, cltr->sched.io.count, cltr->procs.idles  );
-}
+#if defined(CFA_HAVE_LINUX_IO_URING_H)
+	static void assign_io($io_context ** data, size_t count, dlist(processor) & list) {
+		processor * it = &list`first;
+		while(it) {
+			/* paranoid */ verifyf( it, "Unexpected null iterator\n");
+			/* paranoid */ verifyf( it->io.ctx->cq.id < count, "Processor %p has id %u above count %zu\n", it, it->rdq.id, count);
+			data[it->io.ctx->cq.id] = it->io.ctx;
+			it = &(*it)`next;
+		}
+	}
+
+	static void reassign_cltr_io(struct cluster * cltr) {
+		assign_io(cltr->sched.io.data, cltr->sched.io.count, cltr->procs.actives);
+		assign_io(cltr->sched.io.data, cltr->sched.io.count, cltr->procs.idles  );
+	}
+#else
+	static void reassign_cltr_io(struct cluster *) {}
+#endif
 
 static void fix_times( __timestamp_t * volatile & tscs, unsigned count ) {