diff --git a/benchmarks/unistd_benchmark.cpp b/benchmarks/unistd_benchmark.cpp
index 7e2ac30..94be1dd 100644
--- a/benchmarks/unistd_benchmark.cpp
+++ b/benchmarks/unistd_benchmark.cpp
@@ -41,6 +41,8 @@
 }
 BENCHMARK(BM_unistd_getpid_syscall);
 
+#if defined(__BIONIC__)
+
 // Stop GCC optimizing out our pure function.
 /* Must not be static! */ pid_t (*gettid_fp)() = gettid;
 
@@ -55,6 +57,8 @@
 }
 BENCHMARK(BM_unistd_gettid);
 
+#endif
+
 static void BM_unistd_gettid_syscall(int iters) {
   StartBenchmarkTiming();