diff --git a/src/auto/configure b/src/auto/configure
index c1d477c..e65884c 100755
--- a/src/auto/configure
+++ b/src/auto/configure
@@ -4556,7 +4556,7 @@
   { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
 $as_echo "yes" >&6; }
   MACOS_X=yes
-  CPPFLAGS="$CPPFLAGS -D_DARWIN_C_SOURCE -DMACOS_X"
+  CPPFLAGS="$CPPFLAGS -DMACOS_X"
 
   { $as_echo "$as_me:${as_lineno-$LINENO}: checking --disable-darwin argument" >&5
 $as_echo_n "checking --disable-darwin argument... " >&6; }