diff --git a/host/include/crossystem.h b/host/include/crossystem.h
index 71acc84145..c116b0c206 100644
--- a/host/include/crossystem.h
+++ b/host/include/crossystem.h
@@ -6,6 +6,10 @@
 #ifndef VBOOT_REFERENCE_CROSSYSTEM_H_
 #define VBOOT_REFERENCE_CROSSYSTEM_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /* Reads a system property integer.
  *
  * Returns the property value, or -1 if error. */
@@ -28,4 +32,8 @@ int VbSetSystemPropertyInt(const char* name, int value);
  * Returns 0 if success, -1 if error. */
 int VbSetSystemPropertyString(const char* name, const char* value);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif  /* VBOOT_REFERENCE__CROSSYSTEM_H_ */