diff --git a/public/app/features/expressions/components/__snapshots__/hysteresis.test.ts.snap b/public/app/features/expressions/components/__snapshots__/hysteresis.test.ts.snap
index 452fcd7305a..6af902b384d 100644
--- a/public/app/features/expressions/components/__snapshots__/hysteresis.test.ts.snap
+++ b/public/app/features/expressions/components/__snapshots__/hysteresis.test.ts.snap
@@ -72,7 +72,6 @@ exports[`thresholdReducer should update Threshold Type, and unloadEvaluator para
     {
       "evaluator": {
         "params": [
-          10,
           0,
         ],
         "type": "lt",
@@ -90,7 +89,6 @@ exports[`thresholdReducer should update Threshold Type, and unloadEvaluator para
       "type": "query",
       "unloadEvaluator": {
         "params": [
-          10,
           0,
         ],
         "type": "gt",
diff --git a/public/app/features/expressions/components/hysteresis.test.ts b/public/app/features/expressions/components/hysteresis.test.ts
index 7f802aa13f7..13a87d022e3 100644
--- a/public/app/features/expressions/components/hysteresis.test.ts
+++ b/public/app/features/expressions/components/hysteresis.test.ts
@@ -159,7 +159,7 @@ describe('thresholdReducer', () => {
     expect(newState.conditions[0].evaluator.type).toEqual(EvalFunction.IsBelow);
     expect(newState.conditions[0].unloadEvaluator?.type).toEqual(EvalFunction.IsAbove);
     expect(onError).toHaveBeenCalledWith(undefined);
-    expect(newState.conditions[0].unloadEvaluator?.params[0]).toEqual(10);
+    expect(newState.conditions[0].unloadEvaluator?.params[0]).toEqual(0);
   });
   it('Should update unlooadEvaluator when checking hysteresis', () => {
     const initialState: ThresholdExpressionQuery = {
diff --git a/public/app/features/expressions/components/thresholdReducer.ts b/public/app/features/expressions/components/thresholdReducer.ts
index 503baa3e727..17ccf5d233b 100644
--- a/public/app/features/expressions/components/thresholdReducer.ts
+++ b/public/app/features/expressions/components/thresholdReducer.ts
@@ -33,6 +33,9 @@ export const thresholdReducer = createReducer<ThresholdExpressionQuery>(
       //set new type in evaluator
       state.conditions[0].evaluator.type = typeInPayload;
 
+      //reset params
+      state.conditions[0].evaluator.params = [0];
+
       // check if hysteresis is checked
       const hsyteresisIsChecked = Boolean(state.conditions[0].unloadEvaluator);