diff --git a/libc/Android.bp b/libc/Android.bp
index b5ff680..e6f69c2 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -790,6 +790,53 @@
 }
 
 // ========================================================
+// icu4x_bionic.a - Thin Rust wrapper around ICU4X
+// ========================================================
+
+rust_ffi_static {
+    name: "libicu4x_bionic",
+    crate_name: "icu4x_bionic",
+    crate_root: "bionic/icu4x.rs",
+    edition: "2021",
+    features: [],
+    rustlibs: [
+        "//external/rust/android-crates-io/crates/icu_casemap:libicu_casemap",
+        "//external/rust/android-crates-io/crates/icu_collections:libicu_collections",
+        "//external/rust/android-crates-io/crates/icu_properties:libicu_properties",
+    ],
+    apex_available: [
+        "//apex_available:platform",
+        "//apex_available:anyapex",
+    ],
+    vendor_available: true,
+    product_available: true,
+    ramdisk_available: true,
+    vendor_ramdisk_available: true,
+    recovery_available: true,
+    native_bridge_supported: true,
+    sdk_version: "minimum",
+    defaults: ["linux_bionic_supported"],
+}
+
+// current rust implementation detail; will be removed as part of a larger cleanup later
+// go/android-mto-staticlibs-in-make
+cc_rustlibs_for_make {
+    name: "libstatic_rustlibs_for_make",
+    whole_static_libs: ["libicu4x_bionic"],
+    apex_available: [
+        "//apex_available:platform",
+        "//apex_available:anyapex",
+    ],
+    vendor_available: true,
+    product_available: true,
+    ramdisk_available: true,
+    vendor_ramdisk_available: true,
+    recovery_available: true,
+    native_bridge_supported: true,
+    defaults: ["linux_bionic_supported"],
+}
+
+// ========================================================
 // libc_bionic.a - home-grown C library code
 // ========================================================
 
@@ -870,7 +917,6 @@
         "bionic/grp_pwd_file.cpp",
         "bionic/heap_zero_init.cpp",
         "bionic/iconv.cpp",
-        "bionic/icu_wrappers.cpp",
         "bionic/ifaddrs.cpp",
         "bionic/inotify_init.cpp",
         "bionic/ioctl.cpp",
@@ -1182,6 +1228,7 @@
     whole_static_libs: [
         "//external/llvm-libc:llvmlibc",
         "libsystemproperties",
+        "libicu4x_bionic",
     ],
 
     cppflags: ["-Wold-style-cast"],
@@ -1433,7 +1480,6 @@
         "bionic/android_mallopt.cpp",
         "bionic/gwp_asan_wrappers.cpp",
         "bionic/heap_tagging.cpp",
-        "bionic/icu.cpp",
         "bionic/malloc_common.cpp",
         "bionic/malloc_common_dynamic.cpp",
         "bionic/android_profiling_dynamic.cpp",
@@ -1452,7 +1498,6 @@
         "bionic/android_mallopt.cpp",
         "bionic/gwp_asan_wrappers.cpp",
         "bionic/heap_tagging.cpp",
-        "bionic/icu_static.cpp",
         "bionic/malloc_common.cpp",
         "bionic/malloc_limit.cpp",
     ],
diff --git a/libc/bionic/icu.cpp b/libc/bionic/icu.cpp
deleted file mode 100644
index c11b9d6..0000000
--- a/libc/bionic/icu.cpp
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *  * Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include "private/icu.h"
-
-#include <dirent.h>
-#include <dlfcn.h>
-#include <pthread.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <async_safe/log.h>
-
-static void* g_libicu_handle = nullptr;
-
-static bool __find_icu() {
-  g_libicu_handle = dlopen("libicu.so", RTLD_LOCAL);
-  if (g_libicu_handle == nullptr) {
-    async_safe_format_log(ANDROID_LOG_ERROR, "bionic-icu", "couldn't open libicu.so: %s",
-                          dlerror());
-    return false;
-  }
-
-  return true;
-}
-
-void* __find_icu_symbol(const char* symbol_name) {
-  static bool found_icu = __find_icu();
-  if (!found_icu) return nullptr;
-
-  void* symbol = dlsym(g_libicu_handle, symbol_name);
-  if (symbol == nullptr) {
-    async_safe_format_log(ANDROID_LOG_ERROR, "bionic-icu", "couldn't find %s", symbol_name);
-  }
-  return symbol;
-}
diff --git a/libc/bionic/icu4x.rs b/libc/bionic/icu4x.rs
new file mode 100644
index 0000000..939ba2f
--- /dev/null
+++ b/libc/bionic/icu4x.rs
@@ -0,0 +1,98 @@
+// Copyright (C) 2025 The Android Open Source Project
+// SPDX-License-Identifier: Apache-2.0
+
+#![allow(missing_docs)] // Not particularly useful to document these thin wrappers
+
+//! This is a thin wrapper around ICU4X for use in Bionic
+
+use icu_casemap::CaseMapper;
+use icu_collections::codepointtrie::TrieValue;
+use icu_properties::props::*;
+use icu_properties::{CodePointMapData, CodePointSetData};
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_general_category(ch: u32) -> u8 {
+    CodePointMapData::<GeneralCategory>::new().get32(ch) as u8
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_east_asian_width(ch: u32) -> u8 {
+    CodePointMapData::<EastAsianWidth>::new().get32(ch).to_u32() as u8
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_hangul_syllable_type(ch: u32) -> u8 {
+    CodePointMapData::<HangulSyllableType>::new().get32(ch).to_u32() as u8
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_alphabetic(ch: u32) -> bool {
+    CodePointSetData::new::<Alphabetic>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_default_ignorable_code_point(ch: u32) -> bool {
+    CodePointSetData::new::<DefaultIgnorableCodePoint>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_lowercase(ch: u32) -> bool {
+    CodePointSetData::new::<Lowercase>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_alnum(ch: u32) -> bool {
+    CodePointSetData::new::<Alnum>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_blank(ch: u32) -> bool {
+    CodePointSetData::new::<Blank>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_graph(ch: u32) -> bool {
+    CodePointSetData::new::<Graph>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_print(ch: u32) -> bool {
+    CodePointSetData::new::<Print>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_xdigit(ch: u32) -> bool {
+    CodePointSetData::new::<Xdigit>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_white_space(ch: u32) -> bool {
+    CodePointSetData::new::<WhiteSpace>().contains32(ch)
+}
+
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_is_uppercase(ch: u32) -> bool {
+    CodePointSetData::new::<Uppercase>().contains32(ch)
+}
+
+/// Convert a code point to uppercase
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_to_upper(ch: u32) -> u32 {
+    let Ok(ch) = char::try_from(ch) else {
+        return ch;
+    };
+    let cm = CaseMapper::new();
+
+    cm.simple_uppercase(ch) as u32
+}
+
+/// Convert a code point to lowercase
+#[no_mangle]
+pub extern "C" fn __icu4x_bionic_to_lower(ch: u32) -> u32 {
+    let Ok(ch) = char::try_from(ch) else {
+        return ch;
+    };
+    let cm = CaseMapper::new();
+
+    cm.simple_lowercase(ch) as u32
+}
diff --git a/libc/bionic/icu_static.cpp b/libc/bionic/icu_static.cpp
deleted file mode 100644
index cf24a38..0000000
--- a/libc/bionic/icu_static.cpp
+++ /dev/null
@@ -1,34 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *  * Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include "private/icu.h"
-
-// We don't have dlopen/dlsym for static binaries yet.
-void* __find_icu_symbol(const char*) {
-  return nullptr;
-}
diff --git a/libc/bionic/icu_wrappers.cpp b/libc/bionic/icu_wrappers.cpp
deleted file mode 100644
index 523f5a6..0000000
--- a/libc/bionic/icu_wrappers.cpp
+++ /dev/null
@@ -1,42 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *  * Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *  * Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
- * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
- * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
- * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#include "private/icu.h"
-
-int8_t __icu_charType(wint_t wc) {
-  typedef int8_t (*u_charType_t)(UChar32);
-  static auto u_charType = reinterpret_cast<u_charType_t>(__find_icu_symbol("u_charType"));
-  return u_charType ? u_charType(wc) : -1;
-}
-
-int32_t __icu_getIntPropertyValue(wint_t wc, UProperty property) {
-  typedef int32_t (*u_getIntPropertyValue_t)(UChar32, UProperty);
-  static auto u_getIntPropertyValue =
-      reinterpret_cast<u_getIntPropertyValue_t>(__find_icu_symbol("u_getIntPropertyValue"));
-  return u_getIntPropertyValue ? u_getIntPropertyValue(wc, property) : 0;
-}
diff --git a/libc/bionic/wctype.cpp b/libc/bionic/wctype.cpp
index 94597d9..8d0733d 100644
--- a/libc/bionic/wctype.cpp
+++ b/libc/bionic/wctype.cpp
@@ -35,7 +35,7 @@
 #include <wchar.h>
 
 #include "bionic/macros.h"
-#include "private/icu.h"
+#include "private/icu4x.h"
 
 enum {
   WC_TYPE_INVALID = 0,
@@ -54,60 +54,65 @@
   WC_TYPE_MAX
 };
 
-static u_hasBinaryProperty_t __find_u_hasBinaryProperty() {
-  static auto u_hasBinaryProperty =
-      reinterpret_cast<u_hasBinaryProperty_t>(__find_icu_symbol("u_hasBinaryProperty"));
-  return u_hasBinaryProperty;
+#define DO_ISW(prop_name, narrow_fn) \
+  if (__predict_true(wc < 0x80)) {   \
+    return narrow_fn(wc);            \
+  }                                  \
+  return __icu4x_bionic_is_##prop_name(wc);
+
+int iswalnum(wint_t wc) {
+  DO_ISW(alnum, isalnum);
 }
-
-#define DO_ISW(icu_constant, narrow_fn) \
-  u_hasBinaryProperty_t u_hasBinaryProperty; \
-  if (__predict_true(wc < 0x80) || \
-      !(u_hasBinaryProperty = __find_u_hasBinaryProperty())) { \
-    return narrow_fn(wc); \
-  } \
-  return u_hasBinaryProperty(wc, icu_constant); \
-
-int iswalnum(wint_t wc) { DO_ISW(UCHAR_POSIX_ALNUM, isalnum); }
 __strong_alias(iswalnum_l, iswalnum);
-int iswalpha(wint_t wc) { DO_ISW(UCHAR_ALPHABETIC, isalpha); }
+int iswalpha(wint_t wc) {
+  DO_ISW(alphabetic, isalpha);
+}
 __strong_alias(iswalpha_l, iswalpha);
-int iswblank(wint_t wc) { DO_ISW(UCHAR_POSIX_BLANK, isblank); }
+int iswblank(wint_t wc) {
+  DO_ISW(blank, isblank);
+}
 __strong_alias(iswblank_l, iswblank);
-int iswgraph(wint_t wc) { DO_ISW(UCHAR_POSIX_GRAPH, isgraph); }
+int iswgraph(wint_t wc) {
+  DO_ISW(graph, isgraph);
+}
 __strong_alias(iswgraph_l, iswgraph);
-int iswlower(wint_t wc) { DO_ISW(UCHAR_LOWERCASE, islower); }
+int iswlower(wint_t wc) {
+  DO_ISW(lowercase, islower);
+}
 __strong_alias(iswlower_l, iswlower);
-int iswprint(wint_t wc) { DO_ISW(UCHAR_POSIX_PRINT, isprint); }
+int iswprint(wint_t wc) {
+  DO_ISW(print, isprint);
+}
 __strong_alias(iswprint_l, iswprint);
-int iswspace(wint_t wc) { DO_ISW(UCHAR_WHITE_SPACE, isspace); }
+int iswspace(wint_t wc) {
+  DO_ISW(white_space, isspace);
+}
 __strong_alias(iswspace_l, iswspace);
-int iswupper(wint_t wc) { DO_ISW(UCHAR_UPPERCASE, isupper); }
+int iswupper(wint_t wc) {
+  DO_ISW(uppercase, isupper);
+}
 __strong_alias(iswupper_l, iswupper);
-int iswxdigit(wint_t wc) { DO_ISW(UCHAR_POSIX_XDIGIT, isxdigit); }
+int iswxdigit(wint_t wc) {
+  DO_ISW(xdigit, isxdigit);
+}
 __strong_alias(iswxdigit_l, iswxdigit);
 
 int iswcntrl(wint_t wc) {
   if (wc < 0x80) return iscntrl(wc);
-  typedef int8_t (*FnT)(UChar32);
-  static auto u_charType = reinterpret_cast<FnT>(__find_icu_symbol("u_charType"));
-  return u_charType ? (u_charType(wc) == U_CONTROL_CHAR) : iscntrl(wc);
+  return __icu4x_bionic_general_category(wc) == U_CONTROL_CHAR;
 }
 __strong_alias(iswcntrl_l, iswcntrl);
 
 int iswdigit(wint_t wc) {
   if (wc < 0x80) return isdigit(wc);
-  typedef UBool (*FnT)(UChar32);
-  static auto u_isdigit = reinterpret_cast<FnT>(__find_icu_symbol("u_isdigit"));
-  return u_isdigit ? u_isdigit(wc) : isdigit(wc);
+  return __icu4x_bionic_general_category(wc) == U_DECIMAL_NUMBER;
 }
 __strong_alias(iswdigit_l, iswdigit);
 
 int iswpunct(wint_t wc) {
   if (wc < 0x80) return ispunct(wc);
-  typedef UBool (*FnT)(UChar32);
-  static auto u_ispunct = reinterpret_cast<FnT>(__find_icu_symbol("u_ispunct"));
-  return u_ispunct ? u_ispunct(wc) : ispunct(wc);
+  int8_t chartype = __icu4x_bionic_general_category(wc);
+  return chartype >= U_DASH_PUNCTUATION && chartype <= U_OTHER_PUNCTUATION;
 }
 __strong_alias(iswpunct_l, iswpunct);
 
@@ -124,18 +129,14 @@
 wint_t towlower(wint_t wc) {
   if (wc < 0x80) return tolower(wc);
 
-  typedef UChar32 (*FnT)(UChar32);
-  static auto u_tolower = reinterpret_cast<FnT>(__find_icu_symbol("u_tolower"));
-  return u_tolower ? u_tolower(wc) : tolower(wc);
+  return __icu4x_bionic_to_lower(wc);
 }
 __strong_alias(towlower_l, towlower);
 
 wint_t towupper(wint_t wc) {
   if (wc < 0x80) return toupper(wc);
 
-  typedef UChar32 (*FnT)(UChar32);
-  static auto u_toupper = reinterpret_cast<FnT>(__find_icu_symbol("u_toupper"));
-  return u_toupper ? u_toupper(wc) : toupper(wc);
+  return __icu4x_bionic_to_upper(wc);
 }
 __strong_alias(towupper_l, towupper);
 
diff --git a/libc/bionic/wcwidth.cpp b/libc/bionic/wcwidth.cpp
index 776321f..633d83e 100644
--- a/libc/bionic/wcwidth.cpp
+++ b/libc/bionic/wcwidth.cpp
@@ -28,7 +28,7 @@
 
 #include <wchar.h>
 
-#include "private/icu.h"
+#include "private/icu4x.h"
 
 int wcwidth(wchar_t wc) {
   // Fast-path ASCII.
@@ -44,38 +44,33 @@
   // pretty arbitrary. See https://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c for more details.
 
   // Fancy unicode control characters?
-  switch (__icu_charType(wc)) {
-   case -1:
-    // No icu4c available; give up.
-    return -1;
-   case U_CONTROL_CHAR:
-    return -1;
-   case U_NON_SPACING_MARK:
-   case U_ENCLOSING_MARK:
-    return 0;
-   case U_FORMAT_CHAR:
-    // A special case for soft hyphen (U+00AD) to match historical practice.
-    // See the tests for more commentary.
-    return (wc == 0x00ad) ? 1 : 0;
+  switch (__icu4x_bionic_general_category(wc)) {
+    case U_CONTROL_CHAR:
+      return -1;
+    case U_NON_SPACING_MARK:
+    case U_ENCLOSING_MARK:
+      return 0;
+    case U_FORMAT_CHAR:
+      // A special case for soft hyphen (U+00AD) to match historical practice.
+      // See the tests for more commentary.
+      return (wc == 0x00ad) ? 1 : 0;
   }
 
   // Medial and final jamo render as zero width when used correctly,
   // so we handle them specially rather than relying on East Asian Width.
-  switch (__icu_getIntPropertyValue(wc, UCHAR_HANGUL_SYLLABLE_TYPE)) {
-   case U_HST_VOWEL_JAMO:
-   case U_HST_TRAILING_JAMO:
-    return 0;
-   case U_HST_LEADING_JAMO:
-   case U_HST_LV_SYLLABLE:
-   case U_HST_LVT_SYLLABLE:
-    return 2;
+  switch (__icu4x_bionic_hangul_syllable_type(wc)) {
+    case U_HST_VOWEL_JAMO:
+    case U_HST_TRAILING_JAMO:
+      return 0;
+    case U_HST_LEADING_JAMO:
+    case U_HST_LV_SYLLABLE:
+    case U_HST_LVT_SYLLABLE:
+      return 2;
   }
 
   // Hangeul choseong filler U+115F is default ignorable, so we check default
   // ignorability only after we've already handled Hangeul jamo above.
-  static auto u_hasBinaryProperty =
-      reinterpret_cast<u_hasBinaryProperty_t>(__find_icu_symbol("u_hasBinaryProperty"));
-  if (u_hasBinaryProperty && u_hasBinaryProperty(wc, UCHAR_DEFAULT_IGNORABLE_CODE_POINT)) return 0;
+  if (__icu4x_bionic_is_default_ignorable_code_point(wc)) return 0;
 
   // A few weird special cases where EastAsianWidth is not helpful for us.
   if (wc >= 0x3248 && wc <= 0x4dff) {
@@ -88,15 +83,15 @@
 
   // The EastAsianWidth property is at least defined by the Unicode standard!
   // https://www.unicode.org/reports/tr11/
-  switch (__icu_getIntPropertyValue(wc, UCHAR_EAST_ASIAN_WIDTH)) {
-   case U_EA_AMBIGUOUS:
-   case U_EA_HALFWIDTH:
-   case U_EA_NARROW:
-   case U_EA_NEUTRAL:
-    return 1;
-   case U_EA_FULLWIDTH:
-   case U_EA_WIDE:
-    return 2;
+  switch (__icu4x_bionic_east_asian_width(wc)) {
+    case U_EA_AMBIGUOUS:
+    case U_EA_HALFWIDTH:
+    case U_EA_NARROW:
+    case U_EA_NEUTRAL:
+      return 1;
+    case U_EA_FULLWIDTH:
+    case U_EA_WIDE:
+      return 2;
   }
 
   return 0;
diff --git a/libc/private/icu.h b/libc/private/icu4x.h
similarity index 68%
rename from libc/private/icu.h
rename to libc/private/icu4x.h
index 8e4aa80..8b7e1d0 100644
--- a/libc/private/icu.h
+++ b/libc/private/icu4x.h
@@ -26,38 +26,20 @@
  * SUCH DAMAGE.
  */
 
-#ifndef _PRIVATE_ICU_H
-#define _PRIVATE_ICU_H
+#pragma once
 
+#include <ctype.h>
 #include <stdint.h>
 #include <wchar.h>
 
-typedef int8_t UBool;
-#define FALSE 0
-#define TRUE 1
-
-typedef int32_t UChar32;
-
-enum UProperty {
-  UCHAR_ALPHABETIC = 0,
-  UCHAR_DEFAULT_IGNORABLE_CODE_POINT = 5,
-  UCHAR_LOWERCASE = 22,
-  UCHAR_POSIX_ALNUM = 44,
-  UCHAR_POSIX_BLANK = 45,
-  UCHAR_POSIX_GRAPH = 46,
-  UCHAR_POSIX_PRINT = 47,
-  UCHAR_POSIX_XDIGIT = 48,
-  UCHAR_UPPERCASE = 30,
-  UCHAR_WHITE_SPACE = 31,
-  UCHAR_EAST_ASIAN_WIDTH = 0x1004,
-  UCHAR_HANGUL_SYLLABLE_TYPE = 0x100b,
-};
-
 enum UCharCategory {
   U_NON_SPACING_MARK = 6,
   U_ENCLOSING_MARK = 7,
+  U_DECIMAL_NUMBER = 9,
   U_CONTROL_CHAR = 15,
   U_FORMAT_CHAR = 16,
+  U_DASH_PUNCTUATION = 19,
+  U_OTHER_PUNCTUATION = 23,
 };
 
 enum UEastAsianWidth {
@@ -78,11 +60,24 @@
   U_HST_LVT_SYLLABLE,
 };
 
-int8_t __icu_charType(wint_t wc);
-int32_t __icu_getIntPropertyValue(wint_t wc, UProperty property);
+__BEGIN_DECLS
 
-typedef UBool (*u_hasBinaryProperty_t)(UChar32, UProperty);
+uint8_t __icu4x_bionic_general_category(uint32_t cp);
+uint8_t __icu4x_bionic_east_asian_width(uint32_t cp);
+uint8_t __icu4x_bionic_hangul_syllable_type(uint32_t cp);
 
-void* __find_icu_symbol(const char* symbol_name);
+bool __icu4x_bionic_is_alphabetic(uint32_t cp);
+bool __icu4x_bionic_is_default_ignorable_code_point(uint32_t cp);
+bool __icu4x_bionic_is_lowercase(uint32_t cp);
+bool __icu4x_bionic_is_alnum(uint32_t cp);
+bool __icu4x_bionic_is_blank(uint32_t cp);
+bool __icu4x_bionic_is_graph(uint32_t cp);
+bool __icu4x_bionic_is_print(uint32_t cp);
+bool __icu4x_bionic_is_xdigit(uint32_t cp);
+bool __icu4x_bionic_is_white_space(uint32_t cp);
+bool __icu4x_bionic_is_uppercase(uint32_t cp);
 
-#endif  // _PRIVATE_ICU_H
+uint32_t __icu4x_bionic_to_upper(uint32_t ch);
+uint32_t __icu4x_bionic_to_lower(uint32_t ch);
+
+__END_DECLS