diff --git a/base/macutils.cc b/base/macutils.cc
index 74b4919..72ca5cb 100644
--- a/base/macutils.cc
+++ b/base/macutils.cc
@@ -83,7 +83,7 @@
   return false;
 }
 
-bool GetOSVersion(int* major, int* minor, int* bugfix) {
+static bool GetOSVersion(int* major, int* minor, int* bugfix) {
   ASSERT(major && minor && bugfix);
   if (!GetGestalt(gestaltSystemVersion, major)) {
     return false;
diff --git a/base/macutils.h b/base/macutils.h
index 35c3d18..e3a4256 100644
--- a/base/macutils.h
+++ b/base/macutils.h
@@ -43,7 +43,6 @@
   kMacOSNewer,         // 10.10+
 };
 
-bool GetOSVersion(int* major, int* minor, int* bugfix);
 MacOSVersionName GetOSVersionName();
 bool GetQuickTimeVersion(std::string* version);