diff --git a/src/runtime/io.cpp b/src/runtime/io.cpp
index 1afebd2fe2..9a8647c4f8 100644
--- a/src/runtime/io.cpp
+++ b/src/runtime/io.cpp
@@ -8,9 +8,10 @@ Author: Leonardo de Moura
 #include <windows.h>
 #elif defined(__APPLE__)
 #include <mach-o/dyld.h>
+#include <unistd.h>
 #else
 // Linux include files
-#include <unistd.h>
+#include <unistd.h> // NOLINT
 #endif
 #include <iostream>
 #include <chrono>
diff --git a/stage0/src/runtime/io.cpp b/stage0/src/runtime/io.cpp
index 1afebd2fe2..cad4eac6b5 100644
--- a/stage0/src/runtime/io.cpp
+++ b/stage0/src/runtime/io.cpp
@@ -8,6 +8,7 @@ Author: Leonardo de Moura
 #include <windows.h>
 #elif defined(__APPLE__)
 #include <mach-o/dyld.h>
+#include <unistd.h>
 #else
 // Linux include files
 #include <unistd.h>