diff --git a/src/undirected_graph.rs b/src/undirected_graph.rs
index bf224c7c43d64853b5882c302c10a8442b5a95c9..05e8e38db0b86bbf3fa63862b41d3f7d76240250 100644
--- a/src/undirected_graph.rs
+++ b/src/undirected_graph.rs
@@ -196,7 +196,7 @@ impl UndirectedGraph {
 
             for automorphism in gens {
                 // NOTE: The automorphisms produced by nauty act on the original graph.
-                let sigma: Vec<i32> = Self::induced_edge_permutation(&self, &self, automorphism);
+                let sigma: Vec<i32> = Self::induced_edge_permutation(self, self, automorphism);
 
                 if compute_edge_orbits {
                     // Take powers of sigma and act on edges of self.
@@ -222,7 +222,7 @@ impl UndirectedGraph {
 
             if sign != 0 {
                 let edge_permutation: Vec<i32> =
-                    Self::induced_edge_permutation(&normal_self, &self, &lab_inv);
+                    Self::induced_edge_permutation(&normal_self, self, &lab_inv);
                 if compute_edge_orbits {
                     normal_self_edge_orbits = (0..self.edges.len()).map(|e| uf.find(e)).collect();
                     // So far these are the edge orbits of self. Finally we apply the isomorphism to get the edge orbits of normal_self.