diff --git a/libc/Android.bp b/libc/Android.bp
index 579c63c..7454d03 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -1342,6 +1342,7 @@
         "bionic/setpgrp.cpp",
         "bionic/sigaction.cpp",
         "bionic/signal.cpp",
+        "bionic/sigprocmask.cpp",
         "bionic/socket.cpp",
         "bionic/spawn.cpp",
         "bionic/stat.cpp",
diff --git a/libc/bionic/signal.cpp b/libc/bionic/signal.cpp
index fbfe0ce..f2e19c2 100644
--- a/libc/bionic/signal.cpp
+++ b/libc/bionic/signal.cpp
@@ -40,7 +40,6 @@
 #include "private/SigSetConverter.h"
 
 extern "C" int __rt_sigpending(const sigset64_t*, size_t);
-extern "C" int __rt_sigprocmask(int, const sigset64_t*, sigset64_t*, size_t);
 extern "C" int ___rt_sigqueueinfo(pid_t, int, siginfo_t*);
 extern "C" int __rt_sigsuspend(const sigset64_t*, size_t);
 extern "C" int __rt_sigtimedwait(const sigset64_t*, siginfo_t*, const timespec*, size_t);
@@ -208,31 +207,6 @@
   return __rt_sigpending(set, sizeof(*set));
 }
 
-int sigprocmask(int how, const sigset_t* bionic_new_set, sigset_t* bionic_old_set) {
-  SigSetConverter new_set;
-  sigset64_t* new_set_ptr = nullptr;
-  if (bionic_new_set != nullptr) {
-    sigemptyset64(&new_set.sigset64);
-    new_set.sigset = *bionic_new_set;
-    new_set_ptr = &new_set.sigset64;
-  }
-
-  SigSetConverter old_set;
-  if (sigprocmask64(how, new_set_ptr, &old_set.sigset64) == -1) {
-    return -1;
-  }
-
-  if (bionic_old_set != nullptr) {
-    *bionic_old_set = old_set.sigset;
-  }
-
-  return 0;
-}
-
-int sigprocmask64(int how, const sigset64_t* new_set, sigset64_t* old_set) {
-  return __rt_sigprocmask(how, new_set, old_set, sizeof(*new_set));
-}
-
 int sigqueue(pid_t pid, int sig, const sigval value) {
   siginfo_t info;
   memset(&info, 0, sizeof(siginfo_t));
diff --git a/libc/bionic/sigprocmask.cpp b/libc/bionic/sigprocmask.cpp
new file mode 100644
index 0000000..00b5df4
--- /dev/null
+++ b/libc/bionic/sigprocmask.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2008 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 <signal.h>
+
+#include "private/SigSetConverter.h"
+
+extern "C" int __rt_sigprocmask(int, const sigset64_t*, sigset64_t*, size_t);
+
+//
+// These need to be kept separate from pthread_sigmask, sigblock, sigsetmask,
+// sighold, and sigset because libsigchain only intercepts sigprocmask so we
+// can't allow clang to decide to inline sigprocmask.
+//
+
+int sigprocmask(int how,
+                const sigset_t* bionic_new_set,
+                sigset_t* bionic_old_set) __attribute__((__noinline__)) {
+  SigSetConverter new_set;
+  sigset64_t* new_set_ptr = nullptr;
+  if (bionic_new_set != nullptr) {
+    sigemptyset64(&new_set.sigset64);
+    new_set.sigset = *bionic_new_set;
+    new_set_ptr = &new_set.sigset64;
+  }
+
+  SigSetConverter old_set;
+  if (sigprocmask64(how, new_set_ptr, &old_set.sigset64) == -1) {
+    return -1;
+  }
+
+  if (bionic_old_set != nullptr) {
+    *bionic_old_set = old_set.sigset;
+  }
+
+  return 0;
+}
+
+int sigprocmask64(int how,
+                  const sigset64_t* new_set,
+                  sigset64_t* old_set) __attribute__((__noinline__)) {
+  return __rt_sigprocmask(how, new_set, old_set, sizeof(*new_set));
+}