diff --git a/stargan/solver.py b/stargan/solver.py
index 39f9fb5..48b381b 100644
--- a/stargan/solver.py
+++ b/stargan/solver.py
@@ -636,7 +636,7 @@ class Solver(object):
                         l1_error += F.l1_loss(gen, gen_noattack)
                         l2_error += F.mse_loss(gen, gen_noattack)
                         l0_error += (gen - gen_noattack).norm(0)
-                        min_dist += (gen - gen_noattack).norm('-inf')
+                        min_dist += (gen - gen_noattack).norm(float('-inf'))
                         n_samples += 1
 
                 # Save the translated images.