diff --git a/.gitignore b/.gitignore
index d3f896b19e..9b2c8b9c51 100644
--- a/.gitignore
+++ b/.gitignore
@@ -13,8 +13,6 @@ thumbs.db
 .bashrc
 .editorconfig
 
-# top-level go.mod is not meant to be checked in
-/go.mod
 # build artifacts
 bundles/
 cli/winresources/*/*.syso
diff --git a/hack/validate/no-module b/hack/validate/no-module
new file mode 100755
index 0000000000..67a9c559ad
--- /dev/null
+++ b/hack/validate/no-module
@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+#
+# Check that no one is trying to commit a go.mod.
+
+SCRIPTDIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+ROOTDIR="$(git -C "$SCRIPTDIR" rev-parse --show-toplevel)"
+
+if test -e "${ROOTDIR}/go.mod"; then
+	{
+		echo 'FAIL: go.mod found in repository root!'
+		echo
+		echo '      Moby is not a Go module; please delete go.mod and try again.'
+	} >&2
+	exit 1
+else
+	echo 'PASS: No go.mod found in repository root!'
+fi