diff --git a/include/date/ios.mm b/src/ios.mm
similarity index 100%
rename from include/date/ios.mm
rename to src/ios.mm
diff --git a/src/tz.cpp b/src/tz.cpp
index 325a593..42c9d76 100644
--- a/src/tz.cpp
+++ b/src/tz.cpp
@@ -84,10 +84,11 @@
 #endif  // _WIN32
 
 #include "date/tz_private.h"
-#include "date/ios.h"
 
-#ifndef __APPLE__
-#    define TARGET_OS_IPHONE 0
+#ifdef __APPLE__
+#  include "ios.h"
+#else
+#  define TARGET_OS_IPHONE 0
 #endif
 
 #if USE_OS_TZDB