diff --git a/setup.cfg b/setup.cfg
index d2a66c1b4e0..4e3b2f65200 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -113,6 +113,7 @@ tests =
     flake8-builtins>=1.5.0
     flake8-comprehensions>=3.5.0
     flake8-debugger>=4.0.0
+    flake8-implicit-str-concat>=0.4
     flake8-mutable>=1.2.0
     flake8-simplify>=0.14.0
     flake8-type-checking; python_version > "3.7"
diff --git a/tox.ini b/tox.ini
index 87d23419730..b6b77d7f422 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,6 +8,8 @@ ignore=
     W504
     ; "experimental" SIM9xx rules (flake8-simplify)
     SIM9
+    ; explicitly concatenated strings (flake8-implicit-str-concat)
+    ISC003
 
 per-file-ignores=
     ; TYPE_CHECKING block suggestions