diff --git a/libavdevice/decklink_common.cpp b/libavdevice/decklink_common.cpp
index 82b8bdb585..ac7964cd17 100644
--- a/libavdevice/decklink_common.cpp
+++ b/libavdevice/decklink_common.cpp
@@ -70,7 +70,7 @@ static char *dup_wchar_to_utf8(wchar_t *w)
 #define DECKLINK_STR    OLECHAR *
 #define DECKLINK_STRDUP dup_wchar_to_utf8
 #define DECKLINK_FREE(s) SysFreeString(s)
-#elif __APPLE__
+#elif defined(__APPLE__)
 static char *dup_cfstring_to_utf8(CFStringRef w)
 {
     char s[256];