diff --git a/tests/examples/from-toml-lang.toml b/tests/examples/from-toml-lang.toml
index 7d3de9b..91b1524 100644
--- a/tests/examples/from-toml-lang.toml
+++ b/tests/examples/from-toml-lang.toml
@@ -45,3 +45,7 @@ hosts = [
   name = "Nail"
   sku = 284758393
   color = "gray"
+
+[inline]
+# Test "first" sorting for inline tables
+c = { limit="<3.12", version ="4.12.2"}
\ No newline at end of file
diff --git a/tests/examples/sorted/from-toml-lang-first.toml b/tests/examples/sorted/from-toml-lang-first.toml
index 94d9394..d7bea04 100644
--- a/tests/examples/sorted/from-toml-lang-first.toml
+++ b/tests/examples/sorted/from-toml-lang-first.toml
@@ -37,6 +37,10 @@ connection_max = 5000
 enabled = true # Comment after a boolean
 server = "192.168.1.1"
 
+[inline]
+# Test "first" sorting for inline tables
+c = {version = "4.12.2", limit = "<3.12"}
+
 [owner]
 name = "Tom Preston-Werner"
 dob = 1979-05-27T07:32:00Z # First class dates? Why not?
diff --git a/tests/examples/sorted/from-toml-lang-overrides.toml b/tests/examples/sorted/from-toml-lang-overrides.toml
index c93d813..7e40666 100644
--- a/tests/examples/sorted/from-toml-lang-overrides.toml
+++ b/tests/examples/sorted/from-toml-lang-overrides.toml
@@ -16,6 +16,10 @@ enabled = true # Comment after a boolean
 ports = [8001, 8001, 8002]
 server = "192.168.1.1"
 
+[inline]
+# Test "first" sorting for inline tables
+c = {limit = "<3.12", version = "4.12.2"}
+
 [owner]
 bio = "GitHub Cofounder & CEO\nLikes tater tots and beer."
 dob = 1979-05-27T07:32:00Z # First class dates? Why not?
diff --git a/tests/examples/sorted/from-toml-lang.toml b/tests/examples/sorted/from-toml-lang.toml
index f341d0d..ac43b43 100644
--- a/tests/examples/sorted/from-toml-lang.toml
+++ b/tests/examples/sorted/from-toml-lang.toml
@@ -16,6 +16,10 @@ ports = [8001, 8001, 8002]
 connection_max = 5000
 enabled = true # Comment after a boolean
 
+[inline]
+# Test "first" sorting for inline tables
+c = {limit = "<3.12", version = "4.12.2"}
+
 [owner]
 name = "Tom Preston-Werner"
 organization = "GitHub"
diff --git a/tests/test_toml_sort.py b/tests/test_toml_sort.py
index 39b948e..fde13f0 100644
--- a/tests/test_toml_sort.py
+++ b/tests/test_toml_sort.py
@@ -111,6 +111,7 @@ def test_sort_toml_is_str() -> None:
                 "sort_config_overrides": {
                     "database": SortOverrideConfiguration(first=["ports"]),
                     "owner": SortOverrideConfiguration(first=["name", "dob"]),
+                    "inline.c": SortOverrideConfiguration(first=["version"]),
                 },
             },
         ),
diff --git a/toml_sort/tomlsort.py b/toml_sort/tomlsort.py
index 3c66927..25a0339 100644
--- a/toml_sort/tomlsort.py
+++ b/toml_sort/tomlsort.py
@@ -430,8 +430,9 @@ def sort_keys(
         """
 
         def sort_first(item: TomlSortItem) -> int:
-            if item.keys.base in sort_config.first:
-                return sort_config.first.index(item.keys.base.as_string())
+            for index, value in enumerate(sort_config.first):
+                if value == item.keys.base.key:
+                    return index
             return len(sort_config.first)
 
         items = sorted(items, key=self.key_sort_func)