diff --git a/src/signals/forms.py b/src/signals/forms.py
index 51ff46a..a4a5123 100644
--- a/src/signals/forms.py
+++ b/src/signals/forms.py
@@ -7,6 +7,7 @@
     Pathogen,
     Signal,
     TimeLabelChoices,
+    ActiveChoices
 )
 
 MULTI_SELECT_TOOLTIP_MESSAGE = _('Hold down “Control”, or “Command” on a Mac, to select more than one.')
@@ -26,7 +27,7 @@ class SignalFilterForm(forms.ModelForm):
     )
     search = forms.CharField(min_length=3)
     pathogen = forms.ModelChoiceField(queryset=Pathogen.objects.all(), empty_label='---------')
-    active = forms.NullBooleanField(initial=None)
+    active = forms.TypedMultipleChoiceField(choices=ActiveChoices.choices, coerce=bool, widget=forms.CheckboxSelectMultiple())
     format_type = forms.ChoiceField(choices=[('', '---------')] + FormatChoices.choices)
     source = forms.ModelChoiceField(queryset=SourceSubdivision.objects.all(), empty_label='---------')
     time_label = forms.ChoiceField(choices=[('', '---------')] + TimeLabelChoices.choices, label=_('Temporal Resolution'))
@@ -54,7 +55,6 @@ class Meta:
             }),
             'search': forms.TextInput(attrs={'class': 'form-control', 'placeholder': 'Enter search term'}),
             'pathogen': forms.Select(attrs={'class': 'form-select'}),
-            'active': forms.NullBooleanSelect(attrs={'class': 'form-check mt-3', 'label': "Test <i class='ri-stack-line'></i>"},),
             'available_geography': forms.CheckboxSelectMultiple(attrs={
                 'class': 'form-select',
                 'data-bs-toggle': 'tooltip',
diff --git a/src/signals/models.py b/src/signals/models.py
index ab09199..fbbed86 100644
--- a/src/signals/models.py
+++ b/src/signals/models.py
@@ -41,6 +41,14 @@ class HighValuesAreChoices(models.TextChoices):
     NEUTRAL = 'neutral', _('Neutral')
 
 
+class ActiveChoices(models.TextChoices):
+    """
+    A class representing choices for active signals.
+    """
+    ACTIVE = True, _('Active')
+    HISTORICAL = False, _('Historical')
+
+
 class SignalCategory(TimeStampedModel):
     """
     A model representing a signal category.
diff --git a/src/signals/views.py b/src/signals/views.py
index f63ddbc..daff707 100644
--- a/src/signals/views.py
+++ b/src/signals/views.py
@@ -40,7 +40,9 @@ def get_url_params(self):
             "pathogen": int(self.request.GET.get("pathogen"))
             if self.request.GET.get("pathogen")
             else "",
-            "active": self.request.GET.get("active", "unknown"),
+            "active": [el for el in self.request.GET._getlist("active")]
+            if self.request.GET.get("active")
+            else [True, False],
             "available_geography": [
                 int(el) for el in self.request.GET._getlist("available_geography")
             ]