diff --git a/litellm/caching/redis_cache.py b/litellm/caching/redis_cache.py
index a01a099bcc9..1dd3711e36e 100644
--- a/litellm/caching/redis_cache.py
+++ b/litellm/caching/redis_cache.py
@@ -100,9 +100,8 @@ _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"
 )
 
@@ -1256,8 +1255,9 @@ class RedisCache(BaseCache):
         _used_ttl: Final = self.get_ttl(ttl=ttl)
         key = self.check_and_fix_namespace(key=key)
         try:
+            ttl_arg: Final = "" if _used_ttl is None else str(_used_ttl)
             raw_value: Final = await _redis_client.eval(
-                _INCREMENT_WITH_TTL_LUA, 1, key, value, _used_ttl or 0, "1" if refresh_ttl else "0"
+                _INCREMENT_WITH_TTL_LUA, 1, key, value, ttl_arg, "1" if refresh_ttl else "0"
             )
             result: Final = _LUA_FLOAT.validate_python(raw_value)
 
diff --git a/tests/test_litellm/caching/test_redis_cache.py b/tests/test_litellm/caching/test_redis_cache.py
index d27ab6fe393..5aaa75177ab 100644
--- a/tests/test_litellm/caching/test_redis_cache.py
+++ b/tests/test_litellm/caching/test_redis_cache.py
@@ -1253,7 +1253,7 @@ 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
@@ -1266,4 +1266,22 @@ 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