diff --git a/aero_astro_calc/PlaneStress.py b/aero_astro_calc/PlaneStress.py
index 69bbfd4..1f3f4c6 100644
--- a/aero_astro_calc/PlaneStress.py
+++ b/aero_astro_calc/PlaneStress.py
@@ -1,7 +1,7 @@
 from math import sqrt
 
 from bokeh.models import Arrow
-from bokeh.plotting import figure, output_file, show
+from bokeh.plotting import figure, show
 
 from aero_astro_calc.dependencies.LatexLabel import LatexLabel
 
diff --git a/requirements.txt b/requirements.txt
index 8db176d..f723b28 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 bokeh==1.4.0
 black==19.10b0
+flake8==3.7.9
\ No newline at end of file
diff --git a/setup.cfg b/setup.cfg
new file mode 100644
index 0000000..1d36346
--- /dev/null
+++ b/setup.cfg
@@ -0,0 +1,2 @@
+[flake8]
+max-line-length = 88
\ No newline at end of file