diff --git a/gnu/lib/libdialog/checklist.c b/gnu/lib/libdialog/checklist.c
index 61a636be3c25..c31a9305903c 100644
--- a/gnu/lib/libdialog/checklist.c
+++ b/gnu/lib/libdialog/checklist.c
@@ -70,6 +70,10 @@ int dialog_checklist(unsigned char *title, unsigned char *prompt, int height, in
 	width = MAX(width,check_x+4)+4;
   }
 
+  if (width > COLS)
+	width = COLS;
+  if (height > LINES)
+	height = LINES;
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/inputbox.c b/gnu/lib/libdialog/inputbox.c
index 3e5895d3e0ab..61dd2f21248f 100644
--- a/gnu/lib/libdialog/inputbox.c
+++ b/gnu/lib/libdialog/inputbox.c
@@ -41,6 +41,10 @@ int dialog_inputbox(unsigned char *title, unsigned char *prompt, int height, int
 	width = MAX(i,j) + 4;
   }
 
+  if (width > COLS)
+	width = COLS;
+  if (height > LINES)
+	height = LINES;
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/menubox.c b/gnu/lib/libdialog/menubox.c
index fdb9f05116fc..ed82ae5670bc 100644
--- a/gnu/lib/libdialog/menubox.c
+++ b/gnu/lib/libdialog/menubox.c
@@ -60,6 +60,10 @@ int dialog_menu(unsigned char *title, unsigned char *prompt, int height, int wid
 	width = MAX(width,tag_x+4)+4;
   }
 
+  if (width > COLS)
+	width = COLS;
+  if (height > LINES)
+	height = LINES;
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/msgbox.c b/gnu/lib/libdialog/msgbox.c
index fda3b40641a9..50f6c13b2057 100644
--- a/gnu/lib/libdialog/msgbox.c
+++ b/gnu/lib/libdialog/msgbox.c
@@ -40,6 +40,10 @@ int dialog_msgbox(unsigned char *title, unsigned char *prompt, int height, int w
 	width = MAX(i,j)+4;
   }
 
+  if (width > COLS)
+	width = COLS;
+  if (height > LINES)
+	height = LINES;
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/prgbox.c b/gnu/lib/libdialog/prgbox.c
index 0145389d4000..53275bfd704e 100644
--- a/gnu/lib/libdialog/prgbox.c
+++ b/gnu/lib/libdialog/prgbox.c
@@ -39,6 +39,10 @@ int dialog_prgbox(unsigned char *title, const unsigned char *line, int height, i
     fprintf(stderr, "\nAutosizing is impossible in dialog_prgbox().\n");
     exit(-1);
   }
+  if (width > COLS)
+	width = COLS;
+  if (height > LINES)
+	height = LINES;
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/radiolist.c b/gnu/lib/libdialog/radiolist.c
index 54fce3896fbb..5b8a68fff56d 100644
--- a/gnu/lib/libdialog/radiolist.c
+++ b/gnu/lib/libdialog/radiolist.c
@@ -78,6 +78,10 @@ int dialog_radiolist(unsigned char *title, unsigned char *prompt, int height, in
 	width = MAX(width,check_x+4)+4;
   }
 
+  if (width > COLS)
+	width = COLS;
+  if (height > LINES)
+	height = LINES;
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/textbox.c b/gnu/lib/libdialog/textbox.c
index 099f98ef0e72..0479723e41b6 100644
--- a/gnu/lib/libdialog/textbox.c
+++ b/gnu/lib/libdialog/textbox.c
@@ -89,6 +89,10 @@ int dialog_textbox(unsigned char *title, unsigned char *file, int height, int wi
   buf[bytes_read] = '\0';    /* mark end of valid data */
   page = buf;    /* page is pointer to start of page to be displayed */
 
+  if (width > COLS)
+	width = COLS;
+  if (height > LINES)
+	height = LINES;
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;
diff --git a/gnu/lib/libdialog/yesno.c b/gnu/lib/libdialog/yesno.c
index 1e4f77db4b12..8d253608e6bb 100644
--- a/gnu/lib/libdialog/yesno.c
+++ b/gnu/lib/libdialog/yesno.c
@@ -39,6 +39,10 @@ int dialog_yesno(unsigned char *title, unsigned char * prompt, int height, int w
 	width = MAX(i,j)+4;
   }
 
+  if (width > COLS)
+	width = COLS;
+  if (height > LINES)
+	height = LINES;
   /* center dialog box on screen */
   x = (COLS - width)/2;
   y = (LINES - height)/2;