diff --git a/P04/P04.ipynb b/P04/P04.ipynb
index b33665f..9c4cc4b 100644
--- a/P04/P04.ipynb
+++ b/P04/P04.ipynb
@@ -85,7 +85,7 @@
     "Fstop = 170\n",
     "N     = 1440\n",
     "\n",
-    "ff = np.linspace(0, fs,  N, endpoint=False)\n",
+    "ff = np.linspace(0, fs, N, endpoint=False)\n",
     "nn = np.linspace(0, N,  N, endpoint=False)\n",
     "x = np.ones(N)\n",
     "\n",