diff --git a/lib/Sema/CSApply.cpp b/lib/Sema/CSApply.cpp
index 387c39025f4cb..57fe6d3ee627a 100644
--- a/lib/Sema/CSApply.cpp
+++ b/lib/Sema/CSApply.cpp
@@ -7577,7 +7577,11 @@ Expr *ExprRewriter::finishApply(ApplyExpr *apply, Type openedType,
   // FIXME: handle unwrapping everywhere else
   assert(!unwrapResult);
 
-  assert(!cs.getType(fn)->is<UnresolvedType>());
+  // If this is an UnresolvedType in the system, preserve it.
+  if (cs.getType(fn)->is<UnresolvedType>()) {
+    cs.setType(apply, cs.getType(fn));
+    return apply;
+  }
 
   // We have a type constructor.
   auto metaTy = cs.getType(fn)->castTo<AnyMetatypeType>();
diff --git a/test/SourceKit/CodeComplete/rdar75200446.swift b/test/SourceKit/CodeComplete/rdar75200446.swift
new file mode 100644
index 0000000000000..33a256ce2115f
--- /dev/null
+++ b/test/SourceKit/CodeComplete/rdar75200446.swift
@@ -0,0 +1,3 @@
+// RUN: %sourcekitd-test -req=complete -pos=3:14 %s -- %s
+
+.undefined() /*HERE*/