diff --git a/bin/makefile-cygwin.x86_64-x b/bin/makefile-cygwin.x86_64-x
index 667802e..2c9acb0 100644
--- a/bin/makefile-cygwin.x86_64-x
+++ b/bin/makefile-cygwin.x86_64-x
@@ -24,8 +24,7 @@ DISPOPTFLAGS = -O2 -g3
 FPFLAGS =
 DFLAGS = -DLINUX -DAIX -DOLD_CURSOR \
 	-DBYTESWAP -DFORKCOMM -DNOFORN -DLOGINT  $(XFLAGS) \
-	-DRELEASE=351 -DSYSVSIGNALS \
-	-D_GNU_SOURCE
+	-DRELEASE=351 -DSYSVSIGNALS
 
 LDFLAGS = -L/usr/X11/lib -lX11 -lc -lm -lcrypt
 LDELDFLAGS =  -L/usr/X11/lib -lX11 -lc -lm -lcrypt
diff --git a/bin/makefile-linux.386-x b/bin/makefile-linux.386-x
index 2d61eb5..ce82bd8 100644
--- a/bin/makefile-linux.386-x
+++ b/bin/makefile-linux.386-x
@@ -23,8 +23,7 @@ DISPOPTFLAGS = -O2 -g3
 FPFLAGS =
 DFLAGS = -DLINUX -DAIX -DOLD_CURSOR \
 	-DBYTESWAP -DFORKCOMM -DNOFORN -DLOGINT  $(XFLAGS) \
-	-DRELEASE=351 -DSYSVSIGNALS \
-	-D_GNU_SOURCE
+	-DRELEASE=351 -DSYSVSIGNALS
 
 LDFLAGS = -L/usr/X11/lib -lX11 -lc -lm -lcrypt
 LDELDFLAGS =  -L/usr/X11/lib -lX11 -lc -lm -lcrypt
diff --git a/bin/makefile-linux.armv7l-x b/bin/makefile-linux.armv7l-x
index 059e15c..4959d81 100644
--- a/bin/makefile-linux.armv7l-x
+++ b/bin/makefile-linux.armv7l-x
@@ -23,8 +23,7 @@ DISPOPTFLAGS = -O2 -g3
 FPFLAGS =
 DFLAGS = -DLINUX -DAIX -DOLD_CURSOR \
 	-DBYTESWAP -DFORKCOMM -DNOFORN -DLOGINT  $(XFLAGS) \
-	-DRELEASE=351 -DSYSVSIGNALS \
-	-D_GNU_SOURCE
+	-DRELEASE=351 -DSYSVSIGNALS
 
 LDFLAGS = -L/usr/X11/lib -lX11 -lc -lm -lcrypt
 LDELDFLAGS =  -L/usr/X11/lib -lX11 -lc -lm -lcrypt
diff --git a/bin/makefile-linux.x86_64-x b/bin/makefile-linux.x86_64-x
index 667802e..2c9acb0 100644
--- a/bin/makefile-linux.x86_64-x
+++ b/bin/makefile-linux.x86_64-x
@@ -24,8 +24,7 @@ DISPOPTFLAGS = -O2 -g3
 FPFLAGS =
 DFLAGS = -DLINUX -DAIX -DOLD_CURSOR \
 	-DBYTESWAP -DFORKCOMM -DNOFORN -DLOGINT  $(XFLAGS) \
-	-DRELEASE=351 -DSYSVSIGNALS \
-	-D_GNU_SOURCE
+	-DRELEASE=351 -DSYSVSIGNALS
 
 LDFLAGS = -L/usr/X11/lib -lX11 -lc -lm -lcrypt
 LDELDFLAGS =  -L/usr/X11/lib -lX11 -lc -lm -lcrypt
diff --git a/src/timer.c b/src/timer.c
index 4e77eda..8bbbb70 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -577,17 +577,10 @@ static void int_io_init() {
 #else  /* SYSVSIGNALS in effect... */
 #ifndef DOS
   SIGERRCHK(sigset(SIGIO, getsignaldata), "sigset io");
-#ifdef XWINDOW
-#ifndef __CYGWIN__
-#ifdef LINUX
-  if (fcntl(ConnectionNumber(currentdsp->display_id), F_SETSIG, 0) < 0)
-    perror("fcntl on X fd - SETSIG for input handling failed");
-#else
+#if defined(XWINDOW) && defined(I_SETSIG)
   if (ioctl(ConnectionNumber(currentdsp->display_id), I_SETSIG, S_INPUT) < 0)
     perror("ioctl on X fd - SETSIG for input handling failed");
 #endif
-#endif /* __CYGWIN__ */
-#endif /* XWINDOW */
 
 #ifdef USE_DLPI
   DBPRINT(("INIT ETHER:  Doing I_SETSIG.\n"));