diff --git a/include/villas/sample.h b/include/villas/sample.h
index 4caf3f927..53230a7cf 100644
--- a/include/villas/sample.h
+++ b/include/villas/sample.h
@@ -45,6 +45,7 @@ struct sample {
 	
 	atomic_int refcnt;	/**< Reference counter. */
 	struct pool *pool;	/**< This sample is belong to this memory pool. */
+	struct node *source;	/**< The node from which this sample originates. */
 
 	/** All timestamps are seconds / nano seconds after 1.1.1970 UTC */
 	struct {
diff --git a/lib/node.c b/lib/node.c
index b4aa9dc02..9bfe0a4c6 100644
--- a/lib/node.c
+++ b/lib/node.c
@@ -38,6 +38,9 @@ int node_read(struct node *n, struct sample *smps[], unsigned cnt)
 		nread = n->_vt->read(n, smps, cnt);
 	}
 	
+	for (int i = 0; i < nread; i++)
+		smps[i]->source = n;
+	
 	return nread;
 }