diff --git a/src/core/sys/posix/fcntl.d b/src/core/sys/posix/fcntl.d
index f4a9012d7b2..73e91af3ba8 100644
--- a/src/core/sys/posix/fcntl.d
+++ b/src/core/sys/posix/fcntl.d
@@ -486,6 +486,8 @@ else version( CRuntime_Bionic )
     enum F_WRLCK        = 1;
     enum F_UNLCK        = 2;
 
+    enum LOCK_EX        = 2;
+
     version (X86)
     {
         enum O_CREAT        = 0x40;     // octal     0100
diff --git a/src/core/sys/posix/unistd.d b/src/core/sys/posix/unistd.d
index 3c75aaff2ac..0b7f58566fd 100644
--- a/src/core/sys/posix/unistd.d
+++ b/src/core/sys/posix/unistd.d
@@ -1258,6 +1258,7 @@ else version( FreeBSD )
 else version( CRuntime_Bionic )
 {
     int        fchdir(int) @trusted;
+    int        flock(int, int) @trusted;
     pid_t      getpgid(pid_t) @trusted;
     int        lchown(in char*, uid_t, gid_t);
     int        nice(int) @trusted;
diff --git a/src/rt/cover.d b/src/rt/cover.d
index 1df2606437c..9199d80a395 100644
--- a/src/rt/cover.d
+++ b/src/rt/cover.d
@@ -394,7 +394,9 @@ version (Windows) HANDLE handle(int fd)
 
 void lockFile(int fd)
 {
-    version (Posix)
+    version (CRuntime_Bionic)
+        core.sys.posix.unistd.flock(fd, LOCK_EX); // exclusive lock
+    else version (Posix)
         lockf(fd, F_LOCK, 0); // exclusive lock
     else version (Windows)
     {