diff --git a/apex/Android.bp b/apex/Android.bp
index 100430d..c6c4cbf 100644
--- a/apex/Android.bp
+++ b/apex/Android.bp
@@ -36,6 +36,9 @@
     },
     key: "com.android.runtime.key",
     certificate: ":com.android.runtime.certificate",
+    prebuilts: [
+        "bionic-linker-config",
+    ],
 }
 
 sdk {
@@ -76,3 +79,10 @@
         },
     },
 }
+
+prebuilt_etc {
+    name: "bionic-linker-config",
+    src: "linker.config.txt",
+    filename: "linker.config.txt",
+    installable: false,
+}
diff --git a/apex/linker.config.txt b/apex/linker.config.txt
new file mode 100644
index 0000000..7bac3d6
--- /dev/null
+++ b/apex/linker.config.txt
@@ -0,0 +1,6 @@
+# Extra linker configurations for bionic APEX
+# See https://android.googlesource.com/platform/system/linkerconfig/+/master/README.md#apex_etc_linker_config_txt
+
+[properties]
+# Set bionic APEX as force visible so bionic APEX namespace is accessible via android_get_exported_namespace
+visible = true
diff --git a/libc/include/math.h b/libc/include/math.h
index 7efc83a..8c084b2 100644
--- a/libc/include/math.h
+++ b/libc/include/math.h
@@ -10,12 +10,10 @@
  */
 
 /*
- * from: @(#)fdlibm.h 5.1 93/09/24
- * $FreeBSD$
+ * Originally based on fdlibm.h 5.1 via FreeBSD.
  */
 
-#ifndef _MATH_H_
-#define _MATH_H_
+#pragma once
 
 #include <sys/cdefs.h>
 #include <limits.h>
@@ -408,5 +406,3 @@
 #endif
 
 __END_DECLS
-
-#endif