diff --git a/scribblings/tbn.scrbl b/scribblings/tbn.scrbl
index a8959f7..d6afdfe 100644
--- a/scribblings/tbn.scrbl
+++ b/scribblings/tbn.scrbl
@@ -446,6 +446,18 @@ Pretty prints the node labels of the interaction graph of a TBN.
                                      'b (tbf/state (hash 'a -1) -1)))))
 ]}
 
+@defproc[(sbn-interaction-graph [sbn TBN]) Graph]{
+
+Constructs the interaction graph of @racket[sbn], like
+@racket[tbn-interaction-graph], but the nodes of the graph are labeled
+with variable names only.  This is an adaptation to SBNs, in which all
+weights are 0.  The function does not check whether @racket[sbn] is
+indeed an SBN.
+
+@ex[
+(dotit (sbn-interaction-graph (hash 'a (tbf/state (hash 'b 1) 0)
+                                    'b (tbf/state (hash 'a -1) -1))))
+]}
 
 @section{Reading and printing TBNs and SBNs}
 
diff --git a/tbn.rkt b/tbn.rkt
index b10367b..de8936e 100644
--- a/tbn.rkt
+++ b/tbn.rkt
@@ -49,6 +49,7 @@
    TBN sbn? tbn->network
    build-tbn-state-graph normalized-tbn? normalize-tbn compact-tbn
    tbn-interaction-graph pretty-print-tbn-interaction-graph
+   sbn-interaction-graph
    parse-org-tbn read-org-tbn read-org-sbn tbn->lists sbn->lists
    )
 
@@ -537,6 +538,19 @@
                                (tbn-interaction-graph tbn)))
                     "digraph G {\n\tnode0 [label=\"a:0\"];\n\tnode1 [label=\"b:-1\"];\n\tsubgraph U {\n\t\tedge [dir=none];\n\t\tnode0 -> node0 [label=\"0\"];\n\t\tnode1 -> node1 [label=\"0\"];\n\t}\n\tsubgraph D {\n\t\tnode0 -> node1 [label=\"-1\"];\n\t\tnode1 -> node0 [label=\"1\"];\n\t}\n}\n")))
 
+  (: sbn-interaction-graph (-> TBN Graph))
+  (define (sbn-interaction-graph sbn #:zero-edges [zero-edges #t])
+    (update-graph (tbn-interaction-graph sbn #:zero-edges zero-edges)
+                  #:v-func (match-lambda
+                             [(cons var _) var])))
+
+  (module+ test
+    (test-case "sbn-interaction-graph"
+      (define sbn (hash 'a (tbf/state (hash 'b 2) 0)
+                        'b (tbf/state (hash 'a 2) 0)))
+      (check-equal? (graphviz (sbn-interaction-graph sbn))
+                    "digraph G {\n\tnode0 [label=\"b\"];\n\tnode1 [label=\"a\"];\n\tsubgraph U {\n\t\tedge [dir=none];\n\t\tnode0 -> node1 [label=\"2\"];\n\t\tnode0 -> node0 [label=\"0\"];\n\t\tnode1 -> node1 [label=\"0\"];\n\t}\n\tsubgraph D {\n\t}\n}\n")))
+
   (: parse-org-tbn (->* ((Listof (Listof (U Symbol Real))))
                         (#:headers Boolean
                          #:func-names Boolean)