diff --git a/litellm/caching/redis_cache.py b/litellm/caching/redis_cache.py
index 0e0284ade5b..49f00790978 100644
--- a/litellm/caching/redis_cache.py
+++ b/litellm/caching/redis_cache.py
@@ -105,9 +105,8 @@ _INCREMENT_WITH_FLOOR_LUA: Final = (
 
 _INCREMENT_WITH_TTL_LUA: Final = (
     "local value = redis.call('INCRBYFLOAT', KEYS[1], ARGV[1]) "
-    "local ttl = tonumber(ARGV[2]) "
-    "if ttl > 0 and (ARGV[3] == '1' or redis.call('TTL', KEYS[1]) == -1) then "
-    "redis.call('EXPIRE', KEYS[1], ttl) end "
+    "if ARGV[2] ~= '' and (ARGV[3] == '1' or redis.call('TTL', KEYS[1]) == -1) then "
+    "redis.call('EXPIRE', KEYS[1], tonumber(ARGV[2])) end "
     "return value"
 )
 
@@ -1410,8 +1409,9 @@ class RedisCache(BaseCache):
     async def _incrbyfloat_with_ttl(
         _redis_client: "Redis", key: str, value: float, ttl: int | None, refresh_ttl: bool
     ) -> float:
+        ttl_arg: Final = "" if ttl is None else str(ttl)
         raw_value: Final = await _redis_client.eval(
-            _INCREMENT_WITH_TTL_LUA, 1, key, value, ttl or 0, "1" if refresh_ttl else "0"
+            _INCREMENT_WITH_TTL_LUA, 1, key, value, ttl_arg, "1" if refresh_ttl else "0"
         )
         return _LUA_FLOAT.validate_python(raw_value)
 
diff --git a/tests/unit/caching/test_redis_cache.py b/tests/unit/caching/test_redis_cache.py
index 43c7d56072c..9378a770bd1 100644
--- a/tests/unit/caching/test_redis_cache.py
+++ b/tests/unit/caching/test_redis_cache.py
@@ -1400,11 +1400,11 @@ class _RoundTripCountingRedis:
         self.ttls[name] = time
         return True
 
-    async def eval(self, script: str, numkeys: int, key: str, amount: object, ttl_arg: int, refresh: str) -> bytes:
+    async def eval(self, script: str, numkeys: int, key: str, amount: object, ttl_arg: str, refresh: str) -> bytes:
         self.round_trips += 1
         value = self._incr(key, float(amount))  # pyright: ignore[reportArgumentType]  # fake receives the raw float
-        if ttl_arg > 0 and (refresh == "1" or self.ttls.get(key) == -1):
-            self.ttls[key] = ttl_arg
+        if ttl_arg != "" and (refresh == "1" or self.ttls.get(key) == -1):
+            self.ttls[key] = int(ttl_arg)
         return str(value).encode()
 
     def _incr(self, name: str, amount: float) -> float:
@@ -1614,7 +1614,7 @@ async def test_redis_cache_async_increment_arms_ttl_in_the_same_command(
     assert spy.commands == ["eval"]
     script, numkeys, key, amount, ttl, refresh = spy.eval_calls[0]
     assert "INCRBYFLOAT" in script and "EXPIRE" in script and "TTL" in script
-    assert (numkeys, key, amount, ttl, refresh) == (1, expected_key, 0.25, 30, "0")
+    assert (numkeys, key, amount, ttl, refresh) == (1, expected_key, 0.25, "30", "0")
 
 
 @pytest.mark.asyncio
@@ -1627,4 +1627,22 @@ async def test_redis_cache_async_increment_refresh_ttl_sends_refresh_flag(monkey
 
     assert result == 2.5
     assert spy.commands == ["eval"]
-    assert spy.eval_calls[0][3:] == (0.5, 60, "1")
+    assert spy.eval_calls[0][3:] == (0.5, "60", "1")
+
+
+@pytest.mark.parametrize(
+    ("ttl", "default_ttl", "expected_ttl_arg"), [(None, None, ""), (0, None, "0"), (None, 15, "15")]
+)
+@pytest.mark.asyncio
+async def test_redis_cache_async_increment_forwards_ttl_exactly(
+    ttl, default_ttl, expected_ttl_arg, monkeypatch, redis_no_ping
+):
+    monkeypatch.setenv("REDIS_HOST", "https://my-test-host")
+    spy = _SpyRedisCommands(eval_result=b"0.75")
+    redis_cache = _SpyRedisCache(spy)
+    redis_cache.default_ttl = default_ttl
+
+    result = await redis_cache.async_increment(key="spend:key:abc", value=0.75, ttl=ttl)
+
+    assert result == 0.75
+    assert spy.eval_calls[0][4] == expected_ttl_arg