diff --git a/hw/xfree86/common/xf86Init.c b/hw/xfree86/common/xf86Init.c
index 058d09f56..9c31d828d 100644
--- a/hw/xfree86/common/xf86Init.c
+++ b/hw/xfree86/common/xf86Init.c
@@ -401,6 +401,7 @@ InitOutput(ScreenInfo * pScreenInfo, int argc, char **argv)
     MessageType pix24From = X_DEFAULT;
     Bool pix24Fail = FALSE;
     Bool autoconfig = FALSE;
+    Bool sigio_blocked = FALSE;
     GDevPtr configured_device;
 
     xf86Initialising = TRUE;
@@ -819,6 +820,7 @@ InitOutput(ScreenInfo * pScreenInfo, int argc, char **argv)
 #endif
             xf86AccessEnter();
             OsBlockSIGIO();
+            sigio_blocked = TRUE;
         }
     }
 
@@ -924,7 +926,8 @@ InitOutput(ScreenInfo * pScreenInfo, int argc, char **argv)
         AttachUnboundGPU(xf86Screens[0]->pScreen, xf86GPUScreens[i]->pScreen);
 
     xf86VGAarbiterWrapFunctions();
-    OsReleaseSIGIO();
+    if (sigio_blocked)
+        OsReleaseSIGIO();
 
     xf86InitOrigins();