diff --git a/include/ac/string.h b/include/ac/string.h
index b159ec2171..930e757c7c 100644
--- a/include/ac/string.h
+++ b/include/ac/string.h
@@ -21,8 +21,7 @@
 #	ifdef HAVE_STRING_H
 #		include <string.h>
 #	endif
-#	if defined(HAVE_STRINGS_H) && (!defined(HAVE_STRING_H) ||
-		defined(BOTH_STRINGS_H))
+#	if defined(HAVE_STRINGS_H) && (!defined(HAVE_STRING_H) || defined(BOTH_STRINGS_H))
 #		include <strings.h>
 #	endif