diff --git a/AGENTS.md b/AGENTS.md
index 0eb8d1e8..0c0d6818 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -105,6 +105,10 @@ tests for behavior changes and benchmarks for performance improvements. Check
 actual emitted metric values, types and labels through registry gathering;
 configuration or struct assertions alone do not prove publication is correct.
 
+Write invisible or non-ASCII whitespace in source and test data as Go escapes
+(`\u00a0`, `\u3000`, `\u200b`), never as literal characters. Renovate warns about
+hidden Unicode on `main`, and literals are hard to review.
+
 Read [`docs/ci-testing.md`](docs/ci-testing.md) before changing fixtures or test
 skip rules. `WINDOWS_EXPORTER_TEST_COLLECTORS` lists collectors provisioned by CI;
 their failures must fail tests. Optional roles may be absent locally. Report
diff --git a/internal/collector/process/apppool_test.go b/internal/collector/process/apppool_test.go
index 1648c099..d93e5636 100644
--- a/internal/collector/process/apppool_test.go
+++ b/internal/collector/process/apppool_test.go
@@ -68,7 +68,7 @@ var commandLineTests = []struct {
 	{"control character after program", "a \vb", []string{`a`, "\vb"}},
 	{"control character after quoted program", "\"a\"\vb", []string{`a`, "\vb"}},
 	{"control character in argument", "a b\vc\nd", []string{`a`, "b\vc\nd"}},
-	{"unicode spaces", "a b c　d", []string{"a b", "c　d"}},
+	{"unicode spaces", "a\u00a0b c\u3000d", []string{"a\u00a0b", "c\u3000d"}},
 	{"three quotes", `a """b c`, []string{`a`, `"b`, `c`}},
 	{"unicode", `a "Café Пул ✓ Ωμέγα" b`, []string{`a`, `Café Пул ✓ Ωμέγα`, `b`}},
 	{"was command line", wasCommandLine, []string{