diff --git a/merge-check.sh b/merge-check.sh
index 05cee58c..4c5f0a52 100755
--- a/merge-check.sh
+++ b/merge-check.sh
@@ -27,11 +27,12 @@ set -eu
 export GOFLAGS=-mod=vendor GOPROXY=off
 
 # **The unit level's bound, in seconds** (issue 895): the slowest package's own test time of the untagged run, the
-# compile not counted. A run over it fails the check and names the slowest tests. It is 3 s since the tests carry the
+# compile not counted. A run over it fails the check and names the slowest tests. It is 5 s since the tests carry the
 # `integration` tag (design 47 milestone 3): the slowest packages, cmd/mesh-controller and internal/catalogue, measured
-# 2.6-2.8 s in about 2000 small tests each. How-we-build section 5 asks 1 s for the whole unit suite: issue 1055
-# (a catalogue loaded once per package run, fewer source-scanning tests).
-unit_bound=3
+# 2.6-2.8 s on a quiet machine in about 2000 small tests each, and the build node runs the store tests beside this run
+# and other work besides, so twice the measure. How-we-build section 5 asks 1 s for the whole unit suite: issue 1055
+# (a catalogue loaded once per package run, fewer source-scanning tests, the timed run started alone).
+unit_bound=5
 
 # judge_store_tests says each listed test of one package as `go test -v` reported it, and counts in $missing each
 # that did not pass: $1 the package, $2 go test's exit status, $3 the file holding its output, then the names.