diff --git a/src/netcheck/reputation.py b/src/netcheck/reputation.py
index d80824e..503bbec 100644
--- a/src/netcheck/reputation.py
+++ b/src/netcheck/reputation.py
@@ -169,26 +169,43 @@ def captcha_risk(
     ip_type: str,
     abuseipdb_score: int | None,
 ) -> tuple[str, str]:
+    risk, rationale, _ = _captcha_risk_full(firehol_hits, dnsbl_hits, ip_type, abuseipdb_score)
+    return risk, rationale
+
+
+def _captcha_risk_full(
+    firehol_hits: list[str],
+    dnsbl_hits: list[DnsblHit],
+    ip_type: str,
+    abuseipdb_score: int | None,
+) -> tuple[str, str, str]:
     reasons: list[str] = []
+    reasons_ru: list[str] = []
     risk = "low"
     if firehol_hits:
         risk = "high"
         reasons.append(f"listed on {', '.join(firehol_hits)}")
+        reasons_ru.append(f"в блоклисте {', '.join(firehol_hits)}")
     if dnsbl_hits:
         risk = "high"
         reasons.append(f"listed on {', '.join(h.zone for h in dnsbl_hits)}")
+        reasons_ru.append(f"в блоклисте {', '.join(h.zone for h in dnsbl_hits)}")
     if abuseipdb_score is not None and abuseipdb_score >= 50:
         risk = "high"
         reasons.append(f"AbuseIPDB confidence {abuseipdb_score}")
+        reasons_ru.append(f"уверенность AbuseIPDB {abuseipdb_score}")
     elif abuseipdb_score is not None and abuseipdb_score >= 25 and risk == "low":
         risk = "medium"
         reasons.append(f"AbuseIPDB confidence {abuseipdb_score}")
+        reasons_ru.append(f"уверенность AbuseIPDB {abuseipdb_score}")
     if risk == "low" and ip_type == "hosting":
         risk = "medium"
         reasons.append("egress looks like hosting/proxy space, which many sites challenge by default")
+        reasons_ru.append("исходящий адрес похож на хостинг/прокси-пространство, которое многие сайты по умолчанию проверяют капчей")
     if not reasons:
         reasons.append("no blocklist match and the address looks like ordinary end-user space")
-    return risk, "; ".join(reasons)
+        reasons_ru.append("совпадений с блоклистами нет, адрес выглядит как обычное пользовательское пространство")
+    return risk, "; ".join(reasons), "; ".join(reasons_ru)
 
 
 def build_reputation(
@@ -203,7 +220,7 @@ def build_reputation(
     blocked = False
     if dnsbl_outcomes is not None:
         hits, blocked = summarize_dnsbl(dnsbl_outcomes)
-    risk, rationale = captcha_risk(firehol_hits, hits or [], ip_type, abuseipdb_score)
+    risk, rationale, rationale_ru = _captcha_risk_full(firehol_hits, hits or [], ip_type, abuseipdb_score)
     return Reputation(
         internetdb=internetdb,
         firehol_hits=firehol_hits,
@@ -213,6 +230,7 @@ def build_reputation(
         abuseipdb_reports=abuseipdb_reports,
         captcha_risk=risk,
         rationale=rationale,
+        rationale_ru=rationale_ru,
     )
 
 
diff --git a/tests/test_reputation.py b/tests/test_reputation.py
index 347b25e..16920c9 100644
--- a/tests/test_reputation.py
+++ b/tests/test_reputation.py
@@ -156,3 +156,46 @@ def test_build_reputation_without_dnsbl_leaves_the_field_none(api_fixture):
     assert rep.dnsbl_hits is None
     assert rep.dnsbl_query_blocked is False
     assert rep.captcha_risk == "high"
+
+
+_CYRILLIC = set("абвгдеёжзийклмнопрстуфхцчшщъыьэюя")
+
+
+def has_cyrillic(text: str) -> bool:
+    return any(ch in _CYRILLIC for ch in text.lower())
+
+
+def test_build_reputation_rationale_ru_is_populated_and_cyrillic_for_every_reason(api_fixture):
+    cases = [
+        dict(firehol_hits=["firehol_level1"], dnsbl_outcomes=None, ip_type="residential", abuseipdb_score=None),
+        dict(
+            firehol_hits=[],
+            dnsbl_outcomes=[decode_dnsbl("zen.spamhaus.org", ["127.0.0.2"])],
+            ip_type="residential",
+            abuseipdb_score=None,
+        ),
+        dict(firehol_hits=[], dnsbl_outcomes=None, ip_type="residential", abuseipdb_score=90),
+        dict(firehol_hits=[], dnsbl_outcomes=None, ip_type="residential", abuseipdb_score=30),
+        dict(firehol_hits=[], dnsbl_outcomes=None, ip_type="hosting", abuseipdb_score=None),
+        dict(firehol_hits=[], dnsbl_outcomes=None, ip_type="residential", abuseipdb_score=None),
+    ]
+    for case in cases:
+        rep = build_reputation(
+            internetdb=normalize_internetdb(api_fixture("internetdb.json")),
+            firehol_hits=case["firehol_hits"],
+            dnsbl_outcomes=case["dnsbl_outcomes"],
+            ip_type=case["ip_type"],
+            abuseipdb_score=case["abuseipdb_score"],
+            abuseipdb_reports=None,
+        )
+        assert rep.rationale
+        assert rep.rationale_ru
+        assert has_cyrillic(rep.rationale_ru)
+
+
+def test_captcha_risk_public_signature_still_returns_a_two_tuple():
+    result = captcha_risk([], [], "residential", None)
+    assert len(result) == 2
+    risk, rationale = result
+    assert risk == "low"
+    assert rationale