diff --git a/doc/contributing.rst b/doc/contributing.rst
index ef710683b31c8094be90fe39a44d85d2e3e20be4..f4cda099f9d046843a482363bfa77758bd8ff6ce 100644
--- a/doc/contributing.rst
+++ b/doc/contributing.rst
@@ -144,6 +144,7 @@ for a list of error codes):
 - E302: expected 2 blank lines, found 0
 - E303: too many blank lines (3)
 - E701: multiple statements on one line (colon)
+- W504: line break after binary operator
 
 
 The ``pylint`` tool can be *very* opinionated about how you write your code,
@@ -162,7 +163,7 @@ refactoring and convention messages, and a few select warnings (type ``pylint
 To check code with ``flake8`` and ``pylint``, I use the following commands::
 
 
-  flake8 --ignore=E127,E201,E203,E221,E222,E241,E271,E272,E301,E302,E303,E701 fsl
+  flake8 --ignore=E127,E201,E203,E221,E222,E241,E271,E272,E301,E302,E303,E701,W504 fsl
   pylint --extension-pkg-whitelist=numpy,wx \
          --generated-members=np.int8,np.uint8,np.int16,np.uint16,np.int32,np.uint32,np.int64,np.uint64,np.float32,np.float64,np.float128,wx.PyDeadObjectError \
          --disable=R,C,W0511,W0703,W1202 fsl
diff --git a/setup.cfg b/setup.cfg
index 0c604f57e04cd74faf4721accfb0353964f80ebf..3f611406bec88d7cf6c581943a063647ee3b009e 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -22,4 +22,4 @@ testpaths = tests
 addopts   = -v --niters=50 --cov=fsl -m "not longtest"
 
 [flake8]
-ignore = E127,E201,E203,E221,E222,E241,E271,E272,E301,E302,E303,E701
\ No newline at end of file
+ignore = E127,E201,E203,E221,E222,E241,E271,E272,E301,E302,E303,E701,W504
\ No newline at end of file