diff --git a/vlib/runtime/runtime.v b/vlib/runtime/runtime.v
index 842a54487b..7777c00615 100644
--- a/vlib/runtime/runtime.v
+++ b/vlib/runtime/runtime.v
@@ -1,13 +1 @@
-// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
-// Use of this source code is governed by an MIT license
-// that can be found in the LICENSE file.
-
 module runtime
-
-#include <sys/sysinfo.h>
-
-fn C.get_nprocs() int
-
-pub fn nr_cpus() int {
-	return C.get_nprocs()
-}
diff --git a/vlib/runtime/runtime_lin.v b/vlib/runtime/runtime_lin.v
new file mode 100644
index 0000000000..842a54487b
--- /dev/null
+++ b/vlib/runtime/runtime_lin.v
@@ -0,0 +1,13 @@
+// Copyright (c) 2019 Alexander Medvednikov. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+
+module runtime
+
+#include <sys/sysinfo.h>
+
+fn C.get_nprocs() int
+
+pub fn nr_cpus() int {
+	return C.get_nprocs()
+}
diff --git a/vlib/runtime/runtime_mac.v b/vlib/runtime/runtime_mac.v
new file mode 100644
index 0000000000..7345c63217
--- /dev/null
+++ b/vlib/runtime/runtime_mac.v
@@ -0,0 +1,5 @@
+module runtime
+
+pub fn nr_cpus() int {
+	return 0
+}
diff --git a/vlib/runtime/runtime_test.v b/vlib/runtime/runtime_test.v
index c1cb53d999..639a86eb59 100644
--- a/vlib/runtime/runtime_test.v
+++ b/vlib/runtime/runtime_test.v
@@ -1,7 +1,9 @@
 import runtime
 
 fn test_nr_cpus() {
+	$if linux {
 	nr_cpus := runtime.nr_cpus()
 	println(nr_cpus)
 	assert nr_cpus > 0
+	}
 }	
diff --git a/vlib/runtime/runtime_win.v b/vlib/runtime/runtime_win.v
new file mode 100644
index 0000000000..7345c63217
--- /dev/null
+++ b/vlib/runtime/runtime_win.v
@@ -0,0 +1,5 @@
+module runtime
+
+pub fn nr_cpus() int {
+	return 0
+}