diff --git a/MagickCore/string-private.h b/MagickCore/string-private.h
index a833a89..563df32 100644
--- a/MagickCore/string-private.h
+++ b/MagickCore/string-private.h
@@ -18,12 +18,12 @@
 #ifndef _MAGICKCORE_STRING_PRIVATE_H
 #define _MAGICKCORE_STRING_PRIVATE_H
 
+#include "MagickCore/locale_.h"
+
 #if defined(__cplusplus) || defined(c_plusplus)
 extern "C" {
 #endif
 
-#include "MagickCore/locale_.h"
-
 static inline double SiPrefixToDoubleInterval(const char *string,
   const double interval)
 {