diff --git a/base/include/android-base/threads.h b/base/include/android-base/threads.h
index f4ba809..dba1fc6 100644
--- a/base/include/android-base/threads.h
+++ b/base/include/android-base/threads.h
@@ -23,3 +23,8 @@
 uint64_t GetThreadId();
 }
 }  // namespace android
+
+#if defined(__GLIBC__)
+// bionic has this Linux-specifix call, but glibc doesn't.
+extern "C" int tgkill(int tgid, int tid, int sig);
+#endif
diff --git a/base/threads.cpp b/base/threads.cpp
index a71382b..48f6197 100644
--- a/base/threads.cpp
+++ b/base/threads.cpp
@@ -46,3 +46,9 @@
 
 }  // namespace base
 }  // namespace android
+
+#if defined(__GLIBC__)
+int tgkill(int tgid, int tid, int sig) {
+  return syscall(__NR_tgkill, tgid, tid, sig);
+}
+#endif
diff --git a/libbacktrace/Android.bp b/libbacktrace/Android.bp
index b4bf35f..a10e636 100644
--- a/libbacktrace/Android.bp
+++ b/libbacktrace/Android.bp
@@ -42,7 +42,6 @@
     "Backtrace.cpp",
     "BacktraceCurrent.cpp",
     "BacktracePtrace.cpp",
-    "thread_utils.c",
     "ThreadEntry.cpp",
     "UnwindStack.cpp",
     "UnwindStackMap.cpp",
@@ -94,7 +93,6 @@
             ],
 
             static_libs: [
-                "libcutils",
                 "libprocinfo",
             ],
 
@@ -145,7 +143,6 @@
         "backtrace_offline_test.cpp",
         "backtrace_test.cpp",
         "GetPss.cpp",
-        "thread_utils.c",
     ],
 
     cflags: [
@@ -159,7 +156,6 @@
         "libbacktrace",
         "libdexfile",
         "libbase",
-        "libcutils",
         "liblog",
         "libunwindstack",
     ],
diff --git a/libbacktrace/Backtrace.cpp b/libbacktrace/Backtrace.cpp
index 6445a7c..6bec63c 100644
--- a/libbacktrace/Backtrace.cpp
+++ b/libbacktrace/Backtrace.cpp
@@ -23,6 +23,7 @@
 #include <string>
 
 #include <android-base/stringprintf.h>
+#include <android-base/threads.h>
 
 #include <backtrace/Backtrace.h>
 #include <backtrace/BacktraceMap.h>
@@ -31,7 +32,6 @@
 
 #include "BacktraceLog.h"
 #include "UnwindStack.h"
-#include "thread_utils.h"
 
 using android::base::StringPrintf;
 
@@ -124,7 +124,7 @@
   if (pid == BACKTRACE_CURRENT_PROCESS) {
     pid = getpid();
     if (tid == BACKTRACE_CURRENT_THREAD) {
-      tid = gettid();
+      tid = android::base::GetThreadId();
     }
   } else if (tid == BACKTRACE_CURRENT_THREAD) {
     tid = pid;
diff --git a/libbacktrace/BacktraceCurrent.cpp b/libbacktrace/BacktraceCurrent.cpp
index f6f4423..39cb995 100644
--- a/libbacktrace/BacktraceCurrent.cpp
+++ b/libbacktrace/BacktraceCurrent.cpp
@@ -28,13 +28,13 @@
 
 #include <string>
 
+#include <android-base/threads.h>
 #include <backtrace/Backtrace.h>
 #include <backtrace/BacktraceMap.h>
 
 #include "BacktraceAsyncSafeLog.h"
 #include "BacktraceCurrent.h"
 #include "ThreadEntry.h"
-#include "thread_utils.h"
 
 bool BacktraceCurrent::ReadWord(uint64_t ptr, word_t* out_value) {
   if (!VerifyReadWordArgs(ptr, out_value)) {
@@ -76,7 +76,7 @@
     return UnwindFromContext(num_ignore_frames, ucontext);
   }
 
-  if (Tid() != gettid()) {
+  if (Tid() != android::base::GetThreadId()) {
     return UnwindThread(num_ignore_frames);
   }
 
@@ -114,16 +114,17 @@
 static void SignalLogOnly(int, siginfo_t*, void*) {
   ErrnoRestorer restore;
 
-  BACK_ASYNC_SAFE_LOGE("pid %d, tid %d: Received a spurious signal %d\n", getpid(), gettid(),
-                       THREAD_SIGNAL);
+  BACK_ASYNC_SAFE_LOGE("pid %d, tid %d: Received a spurious signal %d\n", getpid(),
+                       static_cast<int>(android::base::GetThreadId()), THREAD_SIGNAL);
 }
 
 static void SignalHandler(int, siginfo_t*, void* sigcontext) {
   ErrnoRestorer restore;
 
-  ThreadEntry* entry = ThreadEntry::Get(getpid(), gettid(), false);
+  ThreadEntry* entry = ThreadEntry::Get(getpid(), android::base::GetThreadId(), false);
   if (!entry) {
-    BACK_ASYNC_SAFE_LOGE("pid %d, tid %d entry not found", getpid(), gettid());
+    BACK_ASYNC_SAFE_LOGE("pid %d, tid %d entry not found", getpid(),
+                         static_cast<int>(android::base::GetThreadId()));
     return;
   }
 
diff --git a/libbacktrace/BacktraceMap.cpp b/libbacktrace/BacktraceMap.cpp
index 399721d..6a967f7 100644
--- a/libbacktrace/BacktraceMap.cpp
+++ b/libbacktrace/BacktraceMap.cpp
@@ -32,8 +32,6 @@
 #include <procinfo/process_map.h>
 #endif
 
-#include "thread_utils.h"
-
 using android::base::StringPrintf;
 
 std::string backtrace_map_t::Name() const {
diff --git a/libbacktrace/BacktracePtrace.cpp b/libbacktrace/BacktracePtrace.cpp
index bf6b16f..9da457d 100644
--- a/libbacktrace/BacktracePtrace.cpp
+++ b/libbacktrace/BacktracePtrace.cpp
@@ -28,7 +28,6 @@
 
 #include "BacktraceLog.h"
 #include "BacktracePtrace.h"
-#include "thread_utils.h"
 
 #if !defined(__APPLE__)
 static bool PtraceRead(pid_t tid, uint64_t addr, word_t* out_value) {
diff --git a/libbacktrace/UnwindStack.cpp b/libbacktrace/UnwindStack.cpp
index e087b2e..4e7f761 100644
--- a/libbacktrace/UnwindStack.cpp
+++ b/libbacktrace/UnwindStack.cpp
@@ -23,10 +23,6 @@
 #include <set>
 #include <string>
 
-#if !defined(__ANDROID__)
-#include <cutils/threads.h>
-#endif
-
 #include <backtrace/Backtrace.h>
 #include <demangle.h>
 #include <unwindstack/Elf.h>
diff --git a/libbacktrace/backtrace_benchmarks.cpp b/libbacktrace/backtrace_benchmarks.cpp
index a23e3b4..099ac60 100644
--- a/libbacktrace/backtrace_benchmarks.cpp
+++ b/libbacktrace/backtrace_benchmarks.cpp
@@ -27,6 +27,7 @@
 #include <string>
 
 #include <android-base/file.h>
+#include <android-base/threads.h>
 
 #include <benchmark/benchmark.h>
 
@@ -154,7 +155,7 @@
 
 static void CreateBacktrace(benchmark::State& state, BacktraceMap* map, BacktraceCreateFn fn) {
   while (state.KeepRunning()) {
-    std::unique_ptr<Backtrace> backtrace(fn(getpid(), gettid(), map));
+    std::unique_ptr<Backtrace> backtrace(fn(getpid(), android::base::GetThreadId(), map));
     backtrace->Unwind(0);
   }
 }
diff --git a/libbacktrace/backtrace_offline_test.cpp b/libbacktrace/backtrace_offline_test.cpp
index 9877f29..7d1027e 100644
--- a/libbacktrace/backtrace_offline_test.cpp
+++ b/libbacktrace/backtrace_offline_test.cpp
@@ -31,9 +31,9 @@
 #include <android-base/macros.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
+#include <android-base/threads.h>
 #include <backtrace/Backtrace.h>
 #include <backtrace/BacktraceMap.h>
-#include <cutils/threads.h>
 
 #include <gtest/gtest.h>
 
@@ -99,7 +99,7 @@
 
 static void* OfflineThreadFunc(void* arg) {
   OfflineThreadArg* fn_arg = reinterpret_cast<OfflineThreadArg*>(arg);
-  fn_arg->tid = gettid();
+  fn_arg->tid = android::base::GetThreadId();
   test_get_context_and_wait(&fn_arg->ucontext, &fn_arg->exit_flag);
   return nullptr;
 }
diff --git a/libbacktrace/backtrace_test.cpp b/libbacktrace/backtrace_test.cpp
index f78a31f..06a32c7 100644
--- a/libbacktrace/backtrace_test.cpp
+++ b/libbacktrace/backtrace_test.cpp
@@ -47,16 +47,15 @@
 #include <android-base/macros.h>
 #include <android-base/stringprintf.h>
 #include <android-base/test_utils.h>
+#include <android-base/threads.h>
 #include <android-base/unique_fd.h>
 #include <cutils/atomic.h>
-#include <cutils/threads.h>
 
 #include <gtest/gtest.h>
 
 // For the THREAD_SIGNAL definition.
 #include "BacktraceCurrent.h"
 #include "backtrace_testlib.h"
-#include "thread_utils.h"
 
 // Number of microseconds per milliseconds.
 #define US_PER_MSEC             1000
@@ -525,7 +524,7 @@
 }
 
 void VerifyLevelThread(void*) {
-  std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), gettid()));
+  std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), android::base::GetThreadId()));
   ASSERT_TRUE(backtrace.get() != nullptr);
   ASSERT_TRUE(backtrace->Unwind(0));
   VERIFY_NO_ERROR(backtrace->GetError().error_code);
@@ -538,7 +537,7 @@
 }
 
 static void VerifyMaxThread(void*) {
-  std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), gettid()));
+  std::unique_ptr<Backtrace> backtrace(Backtrace::Create(getpid(), android::base::GetThreadId()));
   ASSERT_TRUE(backtrace.get() != nullptr);
   ASSERT_TRUE(backtrace->Unwind(0));
   ASSERT_EQ(BACKTRACE_UNWIND_ERROR_EXCEED_MAX_FRAMES_LIMIT, backtrace->GetError().error_code);
@@ -553,7 +552,7 @@
 static void* ThreadLevelRun(void* data) {
   thread_t* thread = reinterpret_cast<thread_t*>(data);
 
-  thread->tid = gettid();
+  thread->tid = android::base::GetThreadId();
   EXPECT_NE(test_level_one(1, 2, 3, 4, ThreadSetState, data), 0);
   return nullptr;
 }
@@ -644,7 +643,7 @@
 static void* ThreadMaxRun(void* data) {
   thread_t* thread = reinterpret_cast<thread_t*>(data);
 
-  thread->tid = gettid();
+  thread->tid = android::base::GetThreadId();
   EXPECT_NE(test_recursive_call(MAX_BACKTRACE_FRAMES+10, ThreadSetState, data), 0);
   return nullptr;
 }
@@ -994,7 +993,7 @@
 static void* ThreadReadTest(void* data) {
   thread_t* thread_data = reinterpret_cast<thread_t*>(data);
 
-  thread_data->tid = gettid();
+  thread_data->tid = android::base::GetThreadId();
 
   // Create two map pages.
   // Mark the second page as not-readable.
@@ -1816,7 +1815,8 @@
 
 static void TestFrameSkipNumbering(create_func_t create_func, map_create_func_t map_create_func) {
   std::unique_ptr<BacktraceMap> map(map_create_func(getpid(), false));
-  std::unique_ptr<Backtrace> backtrace(create_func(getpid(), gettid(), map.get()));
+  std::unique_ptr<Backtrace> backtrace(
+      create_func(getpid(), android::base::GetThreadId(), map.get()));
   backtrace->Unwind(1);
   ASSERT_NE(0U, backtrace->NumFrames());
   ASSERT_EQ(0U, backtrace->GetFrame(0)->num);
diff --git a/libbacktrace/thread_utils.c b/libbacktrace/thread_utils.c
deleted file mode 100644
index e75f56e..0000000
--- a/libbacktrace/thread_utils.c
+++ /dev/null
@@ -1,29 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "thread_utils.h"
-
-#if !defined(__BIONIC__)
-
-// glibc doesn't implement or export tgkill.
-#include <unistd.h>
-#include <sys/syscall.h>
-
-int tgkill(int tgid, int tid, int sig) {
-  return syscall(__NR_tgkill, tgid, tid, sig);
-}
-
-#endif
diff --git a/libbacktrace/thread_utils.h b/libbacktrace/thread_utils.h
deleted file mode 100644
index 9590657..0000000
--- a/libbacktrace/thread_utils.h
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef _LIBBACKTRACE_THREAD_UTILS_H
-#define _LIBBACKTRACE_THREAD_UTILS_H
-
-#include <unistd.h>
-
-#if !defined(__ANDROID__)
-#include <cutils/threads.h>
-#endif
-
-__BEGIN_DECLS
-
-int tgkill(int tgid, int tid, int sig);
-
-__END_DECLS
-
-#endif /* _LIBBACKTRACE_THREAD_UTILS_H */
diff --git a/libmemunreachable/tests/ThreadCapture_test.cpp b/libmemunreachable/tests/ThreadCapture_test.cpp
index 4fbf729..933d65a 100644
--- a/libmemunreachable/tests/ThreadCapture_test.cpp
+++ b/libmemunreachable/tests/ThreadCapture_test.cpp
@@ -32,6 +32,8 @@
 #include "ScopedDisableMalloc.h"
 #include "ScopedPipe.h"
 
+#include <android-base/threads.h>
+
 using namespace std::chrono_literals;
 
 namespace android {
@@ -260,7 +262,7 @@
 
       ThreadCapture thread_capture(ret, heap);
       thread_capture.InjectTestFunc([&](pid_t tid) {
-        syscall(SYS_tgkill, ret, tid, SIGKILL);
+        tgkill(ret, tid, SIGKILL);
         usleep(10000);
       });
       auto list_tids = allocator::vector<pid_t>(heap);
@@ -319,7 +321,7 @@
 
           ThreadCapture thread_capture(child, heap);
           thread_capture.InjectTestFunc([&](pid_t tid) {
-            syscall(SYS_tgkill, child, tid, sig);
+            tgkill(child, tid, sig);
             usleep(10000);
           });
           auto list_tids = allocator::vector<pid_t>(heap);
diff --git a/libunwindstack/tests/UnwindTest.cpp b/libunwindstack/tests/UnwindTest.cpp
index 83695bb..ea992c7 100644
--- a/libunwindstack/tests/UnwindTest.cpp
+++ b/libunwindstack/tests/UnwindTest.cpp
@@ -32,6 +32,7 @@
 #include <vector>
 
 #include <android-base/stringprintf.h>
+#include <android-base/threads.h>
 
 #include <unwindstack/Maps.h>
 #include <unwindstack/Memory.h>
@@ -231,8 +232,7 @@
     usleep(1000);
   }
   ASSERT_NE(0, tid.load());
-  // Portable tgkill method.
-  ASSERT_EQ(0, syscall(__NR_tgkill, getpid(), tid.load(), SIGUSR1)) << "Error: " << strerror(errno);
+  ASSERT_EQ(0, tgkill(getpid(), tid.load(), SIGUSR1)) << "Error: " << strerror(errno);
 
   // Wait for context data.
   void* ucontext;