diff --git a/src/bfu/dialog.h b/src/bfu/dialog.h
index e6a277bd..6236511f 100644
--- a/src/bfu/dialog.h
+++ b/src/bfu/dialog.h
@@ -131,7 +131,7 @@ struct dialog {
 static inline int
 dialog_max_width(struct terminal *term)
 {
-	int width = term->width * 9 / 10 - 2 * DIALOG_LB;
+	int width = term->width * DIALOG_WIDTH_RATIO - 2 * DIALOG_LB;
 
 	int_bounds(&width, 1, int_max(term->width - 2 * DIALOG_LB, 1));
 
@@ -141,7 +141,7 @@ dialog_max_width(struct terminal *term)
 static inline int
 dialog_max_height(struct terminal *term)
 {
-	int height = term->height * 9 / 10 - 2 * DIALOG_TB;
+	int height = term->height * DIALOG_HEIGHT_RATIO - 2 * DIALOG_TB;
 
 	int_bounds(&height, 1, int_max(term->height - 2 * DIALOG_TB, 1));
 
diff --git a/src/setup.h b/src/setup.h
index 7f76be3e..589ff064 100644
--- a/src/setup.h
+++ b/src/setup.h
@@ -51,6 +51,9 @@
 #define DIALOG_FRAME			2
 #define DIALOG_MIN_WIDTH		42
 
+#define DIALOG_WIDTH_RATIO		0.9
+#define DIALOG_HEIGHT_RATIO		0.9
+
 #define DIALOG_LB			(DIALOG_LEFT_BORDER + DIALOG_LEFT_INNER_BORDER + 1)
 #define DIALOG_TB			(DIALOG_TOP_BORDER + DIALOG_TOP_INNER_BORDER + 1)