diff --git a/libc/newhdrgen/yaml/ctype.yaml b/libc/newhdrgen/yaml/ctype.yaml
@@ -1,7 +1,6 @@
 header: ctype.h
 macros: []
-types:
-  - type_name: locale_t
+types: []
 enums: []
 objects: []
 functions:
@@ -101,101 +100,4 @@ functions:
     return_type: int
     arguments:
       - type: int
-  - name: isalnum_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: isalpha_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: isblank_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: iscntrl_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: isdigit_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: isgraph_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: islower_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: isprint_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: ispunct_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: isspace_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: isupper_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: isxdigit_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: tolower_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
-  - name: toupper_l
-    standards:
-      - stdc
-    return_type: int
-    arguments:
-      - type: int
-      - type: locale_t
+    functions: null
diff --git a/libc/newhdrgen/yaml/locale.yaml b/libc/newhdrgen/yaml/locale.yaml
diff --git a/libc/spec/stdc.td b/libc/spec/stdc.td
@@ -4,7 +4,6 @@ def StdC : StandardSpec<"stdc"> {
   PtrType StructTmPtr = PtrType<StructTmType>;
   PtrType TimeTTypePtr = PtrType<TimeTType>;
   NamedType ClockT = NamedType<"clock_t">;
-  NamedType LocaleT = NamedType<"locale_t">;
 
   NamedType DivTType = NamedType<"div_t">;
   NamedType LDivTType = NamedType<"ldiv_t">;
@@ -35,9 +34,7 @@ def StdC : StandardSpec<"stdc"> {
   HeaderSpec CType = HeaderSpec<
       "ctype.h",
       [], // Macros
-      [
-          LocaleT
-      ], // Types
+      [], // Types
       [], // Enumerations
       [
           FunctionSpec<
@@ -110,76 +107,6 @@ def StdC : StandardSpec<"stdc"> {
               RetValSpec<IntType>,
               [ArgSpec<IntType>]
           >,
-          FunctionSpec<
-              "isalnum_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "isalpha_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "isblank_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "iscntrl_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "isdigit_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "isgraph_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "islower_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "isprint_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "ispunct_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "isspace_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "isupper_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "isxdigit_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "tolower_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
-          FunctionSpec<
-              "toupper_l",
-              RetValSpec<IntType>,
-              [ArgSpec<IntType>, ArgSpec<LocaleT>]
-          >,
       ]
   >;
 
@@ -1664,61 +1591,6 @@ def StdC : StandardSpec<"stdc"> {
       ]
   >;
 
-
-  NamedType StructLconv : NamedType<"struct lconv">;
-  PtrType StructLconvPtr : PtrType<StructLconv>;
-
-  HeaderSpec Locale = HeaderSpec<
-     "locale.h",
-      [], // Macros
-      [LocaleT, StructLconv], // Types
-      [], // Enumerations
-      [
-        FunctionSpec<
-          "duplocale",
-          RetValSpec<LocaleT>,
-          [
-            ArgSpec<LocaleT>
-          ]
-        >,
-        FunctionSpec<
-          "freelocale",
-          RetValSpec<VoidType>,
-          [
-            ArgSpec<LocaleT>
-          ]
-        >,
-        FunctionSpec<
-          "localeconv",
-          RetValSpec<StructLconvPtr>,
-          []
-        >,
-        FunctionSpec<
-          "newlocale",
-          RetValSpec<LocaleT>,
-          [
-            ArgSpec<IntType>,
-            ArgSpec<ConstCharPtr>,
-            ArgSpec<LocaleT>
-          ]
-        >,
-        FunctionSpec<
-          "setlocale",
-          RetValSpec<CharPtr>,
-          [
-            ArgSpec<IntType>,
-            ArgSpec<ConstCharPtr>
-          ]
-        >,
-        FunctionSpec<
-          "uselocale",
-          RetValSpec<LocaleT>,
-          [
-            ArgSpec<LocaleT>
-          ]
-        >
-      ]  // Functions
-  >;
 
   let Headers = [
     Assert,
@@ -1741,6 +1613,5 @@ def StdC : StandardSpec<"stdc"> {
     Time,
     UChar,
     WChar,
-    Locale,
   ];
 }
diff --git a/libc/src/CMakeLists.txt b/libc/src/CMakeLists.txt
@@ -40,4 +40,3 @@ add_subdirectory(signal)
 add_subdirectory(spawn)
 add_subdirectory(threads)
 add_subdirectory(time)
-add_subdirectory(locale)
diff --git a/libc/src/ctype/CMakeLists.txt b/libc/src/ctype/CMakeLists.txt
@@ -146,159 +146,3 @@ add_entrypoint_object(
   DEPENDS
     libc.src.__support.ctype_utils
 )
-
-# Do not build the locale versions in overlay mode.
-if(NOT LLVM_LIBC_FULL_BUILD)
-  return()
-endif()
-
-add_entrypoint_object(
-  isalnum_l
-  SRCS
-    isalnum_l.cpp
-  HDRS
-    isalnum_l.h
-  DEPENDS
-    libc.include.ctype
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  isalpha_l
-  SRCS
-    isalpha_l.cpp
-  HDRS
-    isalpha_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  isblank_l
-  SRCS
-    isblank_l.cpp
-  HDRS
-    isblank_l.h
-  DEPENDS
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  iscntrl_l
-  SRCS
-    iscntrl_l.cpp
-  HDRS
-    iscntrl_l.h
-  DEPENDS
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  isdigit_l
-  SRCS
-    isdigit_l.cpp
-  HDRS
-    isdigit_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  isgraph_l
-  SRCS
-    isgraph_l.cpp
-  HDRS
-    isgraph_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  islower_l
-  SRCS
-    islower_l.cpp
-  HDRS
-    islower_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  isprint_l
-  SRCS
-    isprint_l.cpp
-  HDRS
-    isprint_l.h
-  DEPENDS
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  ispunct_l
-  SRCS
-    ispunct_l.cpp
-  HDRS
-    ispunct_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  isspace_l
-  SRCS
-    isspace_l.cpp
-  HDRS
-    isspace_l.h
-  DEPENDS
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  isupper_l
-  SRCS
-    isupper_l.cpp
-  HDRS
-    isupper_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  isxdigit_l
-  SRCS
-    isxdigit_l.cpp
-  HDRS
-    isxdigit_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  tolower_l
-  SRCS
-    tolower_l.cpp
-  HDRS
-    tolower_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
-
-add_entrypoint_object(
-  toupper_l
-  SRCS
-    toupper_l.cpp
-  HDRS
-    toupper_l.h
-  DEPENDS
-    libc.src.__support.ctype_utils
-    libc.hdr.types.locale_t
-)
diff --git a/libc/src/ctype/isalnum.cpp b/libc/src/ctype/isalnum.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isalnum, (int c)) {
   return static_cast<int>(internal::isalnum(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isalnum_l.cpp b/libc/src/ctype/isalnum_l.cpp
diff --git a/libc/src/ctype/isalnum_l.h b/libc/src/ctype/isalnum_l.h
diff --git a/libc/src/ctype/isalpha.cpp b/libc/src/ctype/isalpha.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isalpha, (int c)) {
   return static_cast<int>(internal::isalpha(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isalpha_l.cpp b/libc/src/ctype/isalpha_l.cpp
diff --git a/libc/src/ctype/isalpha_l.h b/libc/src/ctype/isalpha_l.h
diff --git a/libc/src/ctype/isblank.cpp b/libc/src/ctype/isblank.cpp
@@ -13,6 +13,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isblank, (int c)) {
   return static_cast<int>(c == ' ' || c == '\t');
 }

diff --git a/libc/src/ctype/isblank_l.cpp b/libc/src/ctype/isblank_l.cpp
diff --git a/libc/src/ctype/isblank_l.h b/libc/src/ctype/isblank_l.h
diff --git a/libc/src/ctype/iscntrl.cpp b/libc/src/ctype/iscntrl.cpp
@@ -13,6 +13,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, iscntrl, (int c)) {
   const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>(ch < 0x20 || ch == 0x7f);

diff --git a/libc/src/ctype/iscntrl_l.cpp b/libc/src/ctype/iscntrl_l.cpp
diff --git a/libc/src/ctype/iscntrl_l.h b/libc/src/ctype/iscntrl_l.h
diff --git a/libc/src/ctype/isdigit.cpp b/libc/src/ctype/isdigit.cpp
@@ -13,6 +13,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isdigit, (int c)) {
   return static_cast<int>(internal::isdigit(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isdigit_l.cpp b/libc/src/ctype/isdigit_l.cpp
diff --git a/libc/src/ctype/isdigit_l.h b/libc/src/ctype/isdigit_l.h
diff --git a/libc/src/ctype/isgraph.cpp b/libc/src/ctype/isgraph.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isgraph, (int c)) {
   return static_cast<int>(internal::isgraph(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isgraph_l.cpp b/libc/src/ctype/isgraph_l.cpp
diff --git a/libc/src/ctype/isgraph_l.h b/libc/src/ctype/isgraph_l.h
diff --git a/libc/src/ctype/islower.cpp b/libc/src/ctype/islower.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, islower, (int c)) {
   return static_cast<int>(internal::islower(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/islower_l.cpp b/libc/src/ctype/islower_l.cpp
diff --git a/libc/src/ctype/islower_l.h b/libc/src/ctype/islower_l.h
diff --git a/libc/src/ctype/isprint.cpp b/libc/src/ctype/isprint.cpp
@@ -13,6 +13,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isprint, (int c)) {
   const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>((ch - ' ') < 95);

diff --git a/libc/src/ctype/isprint_l.cpp b/libc/src/ctype/isprint_l.cpp
diff --git a/libc/src/ctype/isprint_l.h b/libc/src/ctype/isprint_l.h
diff --git a/libc/src/ctype/ispunct.cpp b/libc/src/ctype/ispunct.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, ispunct, (int c)) {
   const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>(!internal::isalnum(ch) && internal::isgraph(ch));

diff --git a/libc/src/ctype/ispunct_l.cpp b/libc/src/ctype/ispunct_l.cpp
diff --git a/libc/src/ctype/ispunct_l.h b/libc/src/ctype/ispunct_l.h
diff --git a/libc/src/ctype/isspace.cpp b/libc/src/ctype/isspace.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isspace, (int c)) {
   return static_cast<int>(internal::isspace(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isspace_l.cpp b/libc/src/ctype/isspace_l.cpp
diff --git a/libc/src/ctype/isspace_l.h b/libc/src/ctype/isspace_l.h
diff --git a/libc/src/ctype/isupper.cpp b/libc/src/ctype/isupper.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isupper, (int c)) {
   return static_cast<int>(internal::isupper(static_cast<unsigned>(c)));
 }

diff --git a/libc/src/ctype/isupper_l.cpp b/libc/src/ctype/isupper_l.cpp
diff --git a/libc/src/ctype/isupper_l.h b/libc/src/ctype/isupper_l.h
diff --git a/libc/src/ctype/isxdigit.cpp b/libc/src/ctype/isxdigit.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, isxdigit, (int c)) {
   const unsigned ch = static_cast<unsigned>(c);
   return static_cast<int>(internal::isdigit(ch) || (ch | 32) - 'a' < 6);

diff --git a/libc/src/ctype/isxdigit_l.cpp b/libc/src/ctype/isxdigit_l.cpp
diff --git a/libc/src/ctype/isxdigit_l.h b/libc/src/ctype/isxdigit_l.h
diff --git a/libc/src/ctype/tolower.cpp b/libc/src/ctype/tolower.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, tolower, (int c)) { return internal::tolower(c); }
 
 } // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/ctype/tolower_l.cpp b/libc/src/ctype/tolower_l.cpp
diff --git a/libc/src/ctype/tolower_l.h b/libc/src/ctype/tolower_l.h
diff --git a/libc/src/ctype/toupper.cpp b/libc/src/ctype/toupper.cpp
@@ -14,6 +14,8 @@
 
 namespace LIBC_NAMESPACE_DECL {
 
+// TODO: Currently restricted to default locale.
+// These should be extended using locale information.
 LLVM_LIBC_FUNCTION(int, toupper, (int c)) {
   if (internal::islower(c))
     return c - ('a' - 'A');

diff --git a/libc/src/ctype/toupper_l.cpp b/libc/src/ctype/toupper_l.cpp
diff --git a/libc/src/ctype/toupper_l.h b/libc/src/ctype/toupper_l.h
diff --git a/libc/src/locale/CMakeLists.txt b/libc/src/locale/CMakeLists.txt
diff --git a/libc/src/locale/duplocale.cpp b/libc/src/locale/duplocale.cpp
diff --git a/libc/src/locale/duplocale.h b/libc/src/locale/duplocale.h
diff --git a/libc/src/locale/freelocale.cpp b/libc/src/locale/freelocale.cpp
diff --git a/libc/src/locale/freelocale.h b/libc/src/locale/freelocale.h
diff --git a/libc/src/locale/locale.cpp b/libc/src/locale/locale.cpp
diff --git a/libc/src/locale/locale.h b/libc/src/locale/locale.h
diff --git a/libc/src/locale/localeconv.cpp b/libc/src/locale/localeconv.cpp
diff --git a/libc/src/locale/localeconv.h b/libc/src/locale/localeconv.h
diff --git a/libc/src/locale/newlocale.cpp b/libc/src/locale/newlocale.cpp
diff --git a/libc/src/locale/newlocale.h b/libc/src/locale/newlocale.h
diff --git a/libc/src/locale/setlocale.cpp b/libc/src/locale/setlocale.cpp
diff --git a/libc/src/locale/setlocale.h b/libc/src/locale/setlocale.h
diff --git a/libc/src/locale/uselocale.cpp b/libc/src/locale/uselocale.cpp
diff --git a/libc/src/locale/uselocale.h b/libc/src/locale/uselocale.h
diff --git a/libc/test/src/CMakeLists.txt b/libc/test/src/CMakeLists.txt
@@ -82,7 +82,6 @@ add_subdirectory(setjmp)
 add_subdirectory(signal)
 add_subdirectory(spawn)
 add_subdirectory(time)
-add_subdirectory(locale)
 
 if(${LIBC_TARGET_OS} STREQUAL "linux")
   add_subdirectory(pthread)

diff --git a/libc/test/src/locale/CMakeLists.txt b/libc/test/src/locale/CMakeLists.txt
diff --git a/libc/test/src/locale/locale_test.cpp b/libc/test/src/locale/locale_test.cpp
diff --git a/libc/test/src/locale/localeconv_test.cpp b/libc/test/src/locale/localeconv_test.cpp