diff --git a/compiler-rt/test/profile/Posix/gcov-fork.c b/compiler-rt/test/profile/Posix/gcov-fork.c
--- a/compiler-rt/test/profile/Posix/gcov-fork.c
+++ b/compiler-rt/test/profile/Posix/gcov-fork.c
@@ -9,6 +9,7 @@
 // RUN: llvm-cov gcov -t gcov-fork.gcda | FileCheck %s
 
 #include <unistd.h>
+#include <sys/wait.h>
 
 void func1() {}                    // CHECK:      1: [[#@LINE]]:void func1()
 void func2() {}                    // CHECK-NEXT: 2: [[#@LINE]]: