diff --git a/src/Fl_cocoa.mm b/src/Fl_cocoa.mm
index 6f5b8b1..2c7763d 100644
--- a/src/Fl_cocoa.mm
+++ b/src/Fl_cocoa.mm
@@ -4074,15 +4074,6 @@ Window fl_xid(const Fl_Window* w)
 static int calc_mac_os_version() {
   int M, m, b = 0;
   NSAutoreleasePool *localPool = [[NSAutoreleasePool alloc] init];
-#if MAC_OS_X_VERSION_MAX_ALLOWED >= MAC_OS_X_VERSION_10_10
-  if ([NSProcessInfo instancesRespondToSelector:@selector(operatingSystemVersion)]) {
-    NSOperatingSystemVersion version = [[NSProcessInfo processInfo] operatingSystemVersion];
-    M = version.majorVersion;
-    m = version.minorVersion;
-    b = version.patchVersion;
-  }
-  else
-#endif
   {
     NSDictionary * sv = [NSDictionary dictionaryWithContentsOfFile:@"/System/Library/CoreServices/SystemVersion.plist"];
     const char *s = [[sv objectForKey:@"ProductVersion"] UTF8String];