diff --git a/audio/aidl/vts/EffectHelper.h b/audio/aidl/vts/EffectHelper.h
index 685d07d191..2c8edf28fb 100644
--- a/audio/aidl/vts/EffectHelper.h
+++ b/audio/aidl/vts/EffectHelper.h
@@ -250,11 +250,11 @@ class EffectHelper {
                    maxLimit = std::numeric_limits<S>::max();
         if (s.size()) {
             const auto min = *s.begin(), max = *s.rbegin();
-            s.insert(min + (max - min) / 2);
-            if (min != minLimit) {
+            s.insert((min & max) + ((min ^ max) >> 1));
+            if (min > minLimit + 1) {
                 s.insert(min - 1);
             }
-            if (max != maxLimit) {
+            if (max < maxLimit - 1) {
                 s.insert(max + 1);
             }
         }
diff --git a/audio/aidl/vts/VtsHalHapticGeneratorTargetTest.cpp b/audio/aidl/vts/VtsHalHapticGeneratorTargetTest.cpp
index 54caed920e..b33234b04b 100644
--- a/audio/aidl/vts/VtsHalHapticGeneratorTargetTest.cpp
+++ b/audio/aidl/vts/VtsHalHapticGeneratorTargetTest.cpp
@@ -208,7 +208,7 @@ INSTANTIATE_TEST_SUITE_P(
         HapticGeneratorInvalidTest, HapticGeneratorParamTest,
         ::testing::Combine(testing::ValuesIn(EffectFactoryHelper::getAllEffectDescriptors(
                                    IFactory::descriptor, getEffectTypeUuidHapticGenerator())),
-                           testing::Values(MIN_ID - 1),
+                           testing::Values(MIN_ID),
                            testing::Values(HapticGenerator::VibratorScale::NONE),
                            testing::Values(MIN_FLOAT), testing::Values(MIN_FLOAT),
                            testing::Values(MIN_FLOAT)),