diff --git a/go.mod b/go.mod
index 5b629e2..44651e4 100644
--- a/go.mod
+++ b/go.mod
@@ -2,6 +2,8 @@ module github.com/mmb/tmpbbs
 
 go 1.26
 
+toolchain go1.26.6
+
 require (
 	github.com/derekparker/trie v0.0.0-20230829180723-39f4de51ef7d
 	github.com/kyokomi/emoji/v2 v2.2.13
diff --git a/tests/integration/go.mod b/tests/integration/go.mod
index 69f9504..8de0787 100644
--- a/tests/integration/go.mod
+++ b/tests/integration/go.mod
@@ -2,6 +2,8 @@ module github.com/mmb/tmpbbs/tests/integration
 
 go 1.26
 
+toolchain go1.26.6
+
 require (
 	github.com/chromedp/cdproto v0.0.0-20260714215040-dc233986426f
 	github.com/chromedp/chromedp v0.16.0
diff --git a/tools/go.mod b/tools/go.mod
index 6999b04..3a9343d 100644
--- a/tools/go.mod
+++ b/tools/go.mod
@@ -1,6 +1,8 @@
 module github.com/mmb/tmpbbs/tools
 
-go 1.26.4
+go 1.26
+
+toolchain go1.26.6
 
 tool (
 	golang.org/x/text/cmd/gotext