diff --git a/tool_requirements.py b/tool_requirements.py
index 9a0024e..55fbe96 100644
--- a/tool_requirements.py
+++ b/tool_requirements.py
@@ -5,7 +5,7 @@
 # Version requirements for various tools. Checked by tooling (e.g. fusesoc),
 # and inserted into the documentation.
 __TOOL_REQUIREMENTS__ = {
-    'verilator': '4.028',
+    'verilator': '4.040',
     'edalize': '0.2.0',
     'verible': '0.0-520-g650c6cc',
 }