diff --git a/strawberryfields/compilers/passive.py b/strawberryfields/compilers/passive.py
index fb0c58cc7..1c840cfe3 100644
--- a/strawberryfields/compilers/passive.py
+++ b/strawberryfields/compilers/passive.py
@@ -168,7 +168,7 @@ def compile(self, seq, registers):
             elif name == "Interferometer":
                 U = params[0]
                 if U.shape == (1, 1):
-                    T = _apply_one_mode_gate(U[0,0], T, dict_indices[modes[0]])
+                    T = _apply_one_mode_gate(U[0, 0], T, dict_indices[modes[0]])
                 elif U.shape == (2, 2):
                     T = _apply_two_mode_gate(U, T, dict_indices[modes[0]], dict_indices[modes[1]])
                 else:
@@ -179,7 +179,7 @@ def compile(self, seq, registers):
             elif name == "PassiveChannel":
                 T0 = params[0]
                 if T0.shape == (1, 1):
-                    T = _apply_one_mode_gate(T0[0,0], T, dict_indices[modes[0]])
+                    T = _apply_one_mode_gate(T0[0, 0], T, dict_indices[modes[0]])
                 elif T0.shape == (2, 2):
                     T = _apply_two_mode_gate(T0, T, dict_indices[modes[0]], dict_indices[modes[1]])
                 else: