1 files changed, 1 insertions, 1 deletions
diff --git a/typing.cpp b/typing.cpp
index 285173b..a1c544f 100644
--- a/typing.cpp
+++ b/typing.cpp
@@ -283,7 +283,7 @@ Subst::compose(const Subst& delta, const Subst& gamma) // TAPL 22.1.1
 {
 	Subst r;
 	for (Subst::const_iterator g = gamma.begin(); g != gamma.end(); ++g) {
-		Subst::const_iterator d = delta.find(g->second);
+		Subst::const_iterator d = delta.find(*g->second);
 		r.insert(make_pair(g->first, ((d != delta.end()) ? d : g)->second));
 	}
 	for (Subst::const_iterator d = delta.begin(); d != delta.end(); ++d) {