diff --git a/vm/os-windows-nt.cpp b/vm/os-windows-nt.cpp
index c46628d41e..796834a9c4 100755
--- a/vm/os-windows-nt.cpp
+++ b/vm/os-windows-nt.cpp
@@ -51,6 +51,11 @@ u64 nano_count()
 	return count.QuadPart*(1000000000/frequency.QuadPart);
 }
 
+void sleep_nanos(u64 nsec)
+{
+	Sleep((DWORD)(nsec/1000000));
+}
+
 LONG factor_vm::exception_handler(PEXCEPTION_POINTERS pe)
 {
 	PEXCEPTION_RECORD e = (PEXCEPTION_RECORD)pe->ExceptionRecord;
diff --git a/vm/os-windows.cpp b/vm/os-windows.cpp
index 8a7cf9024b..78426b19ca 100755
--- a/vm/os-windows.cpp
+++ b/vm/os-windows.cpp
@@ -126,11 +126,6 @@ segment::~segment()
 		fatal_error("Segment deallocation failed",0);
 }
 
-void sleep_nanos(u64 nsec)
-{
-	Sleep((DWORD)(nsec/1000000));
-}
-
 long getpagesize()
 {
 	static long g_pagesize = 0;
diff --git a/vm/os-windows.hpp b/vm/os-windows.hpp
index 37591a529f..eeac2a42dd 100644
--- a/vm/os-windows.hpp
+++ b/vm/os-windows.hpp
@@ -45,6 +45,7 @@ inline static void early_init() {}
 
 u64 system_micros();
 u64 nano_count();
+void sleep_nanos(u64 nsec);
 long getpagesize();
 
 }
diff --git a/vm/run.cpp b/vm/run.cpp
index ebe3678439..1bb2e0c44e 100755
--- a/vm/run.cpp
+++ b/vm/run.cpp
@@ -20,7 +20,7 @@ void factor_vm::primitive_nano_count()
 
 void factor_vm::primitive_sleep()
 {
-	sleep_nanos(factor_vm::to_unsigned_8(dpop()));
+	sleep_nanos(to_unsigned_8(dpop()));
 }
 
 }
diff --git a/vm/vm.hpp b/vm/vm.hpp
index 04eaf3d2ef..4f82e59598 100755
--- a/vm/vm.hpp
+++ b/vm/vm.hpp
@@ -674,7 +674,6 @@ struct factor_vm
 
 	// os-windows
   #if defined(WINDOWS)
-	void sleep_nanos(u64 nsec);
 	const vm_char *vm_executable_path();
 	const vm_char *default_image_path();
 	void windows_image_path(vm_char *full_path, vm_char *temp_path, unsigned int length);