diff --git a/dev-requirements.txt b/dev-requirements.txt
index db04ebd..d12d986 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -37,7 +37,7 @@ markupsafe==1.1.1         # via jinja2
 mccabe==0.6.1             # via flake8, pylint
 more-itertools==7.1.0     # via pytest
 mypy-extensions==0.4.1    # via mypy
-mypy==0.730
+mypy==0.740
 nodeenv==1.3.3            # via pre-commit
 packaging==19.0           # via pytest, pytest-sugar, tox
 pathtools==0.1.2          # via watchdog
diff --git a/requirements.txt b/requirements.txt
index dd7aa77..7a88b70 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -29,7 +29,7 @@ markupsafe==1.1.1         # via jinja2
 marshmallow==3.0rc8       # via mario
 more-itertools==7.2.0     # via pytest
 mypy-extensions==0.4.1    # via mypy, trio-typing
-mypy==0.730               # via trio-typing
+mypy==0.740               # via trio-typing
 outcome==1.0.0            # via trio
 packaging==19.1           # via pytest, sphinx
 parso==0.4.0              # via mario