diff --git a/htdocs/lib/settings/BookmarkTable.js b/htdocs/lib/settings/BookmarkTable.js
index a0927af..1a15981 100644
--- a/htdocs/lib/settings/BookmarkTable.js
+++ b/htdocs/lib/settings/BookmarkTable.js
@@ -82,7 +82,7 @@ FrequencyEditor.prototype.getInputHtml = function() {
     return '<div class="input-group input-group-sm exponential-input" name="frequency">' +
         '<input class="form-control form-control-sm" type="number" step="1">' +
         '<div class="input-group-append">' +
-            '<select class="input-group-text exponent">' +
+            '<select class="input-group-text exponent" tabindex="-1">' +
                 $.map(FrequencyEditor.suffixes, function(v, k) {
                     // fix lowercase "kHz"
                     if (k === "K") k = "k";
diff --git a/owrx/form/__init__.py b/owrx/form/__init__.py
index f1f7113..6e1e7d4 100644
--- a/owrx/form/__init__.py
+++ b/owrx/form/__init__.py
@@ -375,7 +375,7 @@ class ExponentialInput(Input):
     def render_input_group(self, value, errors):
         append = """
             <div class="input-group-append">
-                <select class="input-group-text exponent" name="{id}-exponent" {disabled}>
+                <select class="input-group-text exponent" name="{id}-exponent" tabindex="-1" {disabled}>
                     <option value="0" selected>{unit}</option>
                     <option value="3">k{unit}</option>
                     <option value="6">M{unit}</option>