diff --git a/contrib/japanese/gdev10v.c b/contrib/japanese/gdev10v.c
index 510a74e870762240453b8f44a10b4936f05edcbc..5b617978f0761ba6354894dfdb62097a43f260a9 100644
--- a/contrib/japanese/gdev10v.c
+++ b/contrib/japanese/gdev10v.c
@@ -68,13 +68,25 @@ static dev_proc_print_page(bj10v_print_page);
 static dev_proc_get_initial_matrix(bj10v_get_initial_matrix);
 #endif
 
+static int
+bj10v_open(gx_device * pdev)
+{
+    if (pdev->HWResolution[0] < 180 ||
+        pdev->HWResolution[1] < 180)
+    {
+        emprintf(pdev->memory, "device requires a resolution of at least 180dpi\n");
+        return_error(gs_error_rangecheck);
+    }
+    return gdev_prn_open(pdev);
+}
+
 #if 0
 gx_device_procs prn_bj10v_procs =
   prn_matrix_procs(gdev_prn_open, bj10v_get_initial_matrix,
     gdev_prn_output_page, gdev_prn_close);
 #endif
 gx_device_procs prn_bj10v_procs =
-  prn_procs(gdev_prn_open, gdev_prn_output_page, gdev_prn_close);
+  prn_procs(bj10v_open, gdev_prn_output_page, gdev_prn_close);
 
 gx_device_printer gs_bj10v_device =
   prn_device(prn_bj10v_procs, "bj10v",
diff --git a/contrib/japanese/gdevalps.c b/contrib/japanese/gdevalps.c
index e6af9cf1694b23704323503dcf1d6e4f0900f18f..c52c4b03b3fee814a4620dee197c4f6508296831 100644
--- a/contrib/japanese/gdevalps.c
+++ b/contrib/japanese/gdevalps.c
@@ -156,12 +156,19 @@ static int
 md_open(gx_device *pdev)
 {
         static const float md_margins[4] =
-         {	MD_SIDE_MARGIN, MD_BOTTOM_MARGIN,
+            {
+                MD_SIDE_MARGIN, MD_BOTTOM_MARGIN,
                 MD_SIDE_MARGIN, MD_TOP_MARGIN
-         };
+            };
 
-        gx_device_set_margins(pdev, md_margins, true);
-        return gdev_prn_open(pdev);
+            if (pdev->HWResolution[0] != 600)
+            {
+                emprintf(pdev->memory, "device must have an X resolution of 600dpi\n");
+                return_error(gs_error_rangecheck);
+            }
+
+            gx_device_set_margins(pdev, md_margins, true);
+            return gdev_prn_open(pdev);
 }
 
 /* MD5000 monochrome mode entrance. */