diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d87fa5203bd52..e846ef9b0d4ff 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -2,9 +2,12 @@ name: CI
 
 on:
   push:
-    branches: master
+    branches:
+      - master
   pull_request:
-    branches: master
+    branches:
+      - master
+      - 1.0.x
 
 env:
   ENV_FILE: environment.yml
diff --git a/ci/code_checks.sh b/ci/code_checks.sh
index 30d3a3ffe5f7b..ea02ddbb81546 100755
--- a/ci/code_checks.sh
+++ b/ci/code_checks.sh
@@ -66,7 +66,7 @@ if [[ -z "$CHECK" || "$CHECK" == "lint" ]]; then
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
     MSG='Linting .pyx code' ; echo $MSG
-    flake8 --format="$FLAKE8_FORMAT" pandas --filename=*.pyx --select=E501,E302,E203,E111,E114,E221,E303,E128,E231,E126,E265,E305,E301,E127,E261,E271,E129,W291,E222,E241,E123,F403,C400,C401,C402,C403,C404,C405,C406,C407,C408,C409,C410,C411
+    flake8 --format="$FLAKE8_FORMAT" pandas --filename=*.pyx --select=E501,E302,E203,E111,E114,E221,E303,E231,E126,E265,E305,E301,E127,E261,E271,E129,W291,E222,E241,E123,F403,C400,C401,C402,C403,C404,C405,C406,C407,C408,C409,C410,C411
     RET=$(($RET + $?)) ; echo $MSG "DONE"
 
     MSG='Linting .pxd and .pxi.in' ; echo $MSG
diff --git a/pandas/core/arrays/interval.py b/pandas/core/arrays/interval.py
index cc41ac1dc19a9..1c7a903df5584 100644
--- a/pandas/core/arrays/interval.py
+++ b/pandas/core/arrays/interval.py
@@ -1070,6 +1070,7 @@ def mid(self):
         points) and is either monotonic increasing or monotonic decreasing,
         else False.
         """
+
     # https://github.com/python/mypy/issues/1362
     # Mypy does not support decorated properties
     @property  # type: ignore
diff --git a/pandas/tests/groupby/test_categorical.py b/pandas/tests/groupby/test_categorical.py
index 1c2de8c8c223f..03e87aeb415e5 100644
--- a/pandas/tests/groupby/test_categorical.py
+++ b/pandas/tests/groupby/test_categorical.py
@@ -497,9 +497,9 @@ def test_dataframe_categorical_ordered_observed_sort(ordered, observed, sort):
         aggr[aggr.isna()] = "missing"
     if not all(label == aggr):
         msg = (
-            f"Labels and aggregation results not consistently sorted\n"
-            + "for (ordered={ordered}, observed={observed}, sort={sort})\n"
-            + "Result:\n{result}"
+            "Labels and aggregation results not consistently sorted\n"
+            f"for (ordered={ordered}, observed={observed}, sort={sort})\n"
+            f"Result:\n{result}"
         )
         assert False, msg
 
diff --git a/setup.cfg b/setup.cfg
index d0570cee6fe10..cf7c5a5ef6563 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -19,6 +19,8 @@ ignore =
     W504,  # line break after binary operator
     E402,  # module level import not at top of file
     E731,  # do not assign a lambda expression, use a def
+    E721,  # do not compare types, use 'isinstance()
+    E741,  # ambiguous variable name 'l' (GH#34150)
     C406,  # Unnecessary list literal - rewrite as a dict literal.
     C408,  # Unnecessary dict call - rewrite as a literal.
     C409,  # Unnecessary list passed to tuple() - rewrite as a tuple literal.