diff --git a/cpp/switchchain_initialtris.cpp b/cpp/switchchain_initialtris.cpp
index b241f78ebf55a849557d146004dfa8091269087e..6daff04207b0bce9e7e21cd1abef76cfb3a38b37 100644
--- a/cpp/switchchain_initialtris.cpp
+++ b/cpp/switchchain_initialtris.cpp
@@ -68,7 +68,8 @@ class SwitchChain {
 //
 // method2 = true  -> take highest degree and finish its pairing completely
 // method2 = false -> take new highest degree after every pairing
-bool greedyConfigurationModel(DegreeSequence& ds, Graph& g, auto& rng, bool method2) {
+template <typename RNG>
+bool greedyConfigurationModel(DegreeSequence& ds, Graph& g, RNG& rng, bool method2) {
     // Similar to Havel-Hakimi but instead of pairing up with the highest ones
     // that remain, simply pair up with random ones
     unsigned int n = ds.size();