diff --git a/config_webrx.py b/config_webrx.py
index e0c1810..9e67241 100644
--- a/config_webrx.py
+++ b/config_webrx.py
@@ -262,7 +262,7 @@ waterfall_colors = [0x30123bff, 0x311542ff, 0x33184aff, 0x341b51ff, 0x351e58ff,
 
 waterfall_min_level = -88  # in dB
 waterfall_max_level = -20
-waterfall_auto_level_margin = {"min": 5, "max": 10}
+waterfall_auto_level_margin = {"min": 3, "max": 10, "min_range": 50}
 
 # Note: When the auto waterfall level button is clicked, the following happens:
 #   [waterfall_min_level] = [current_min_power_level] - [waterfall_auto_level_margin["min"]]
diff --git a/htdocs/openwebrx.js b/htdocs/openwebrx.js
index c597e2d..c71c2df 100644
--- a/htdocs/openwebrx.js
+++ b/htdocs/openwebrx.js
@@ -104,8 +104,11 @@ function waterfallColorsDefault() {
 }
 
 function waterfallColorsAuto(levels) {
-    $("#openwebrx-waterfall-color-min").val(levels.min - waterfall_auto_level_margin.min);
-    $("#openwebrx-waterfall-color-max").val(levels.max + waterfall_auto_level_margin.max);
+    var min_level = levels.min - waterfall_auto_level_margin.min;
+    $("#openwebrx-waterfall-color-min").val(min_level);
+    var max_level = levels.max + waterfall_auto_level_margin.max;
+    max_level = Math.max(min_level + (waterfall_auto_level_margin.min_range || 0), max_level);
+    $("#openwebrx-waterfall-color-max").val(max_level);
     updateWaterfallColors(0);
 }