diff --git a/R/fixed_design_maxcombo.R b/R/fixed_design_maxcombo.R
index a0d76bea..8487ce91 100644
--- a/R/fixed_design_maxcombo.R
+++ b/R/fixed_design_maxcombo.R
@@ -102,7 +102,8 @@ fixed_design_maxcombo <- function(
       enroll_rate = enroll_rate,
       fail_rate = fail_rate,
       fh_test = max_combo_test,
-      upper = gs_b, upar = qnorm(1 - alpha),
+      upper = gs_spending_combo,
+      upar = list(sf = gsDesign::sfLDOF, total_spend = alpha),
       lower = gs_b, lpar = -Inf
     )
   } else {
@@ -111,7 +112,8 @@ fixed_design_maxcombo <- function(
       enroll_rate = enroll_rate,
       fail_rate = fail_rate,
       fh_test = max_combo_test,
-      upper = gs_b, upar = qnorm(1 - alpha),
+      upper = gs_spending_combo,
+      upar = list(sf = gsDesign::sfLDOF, total_spend = alpha),
       lower = gs_b, lpar = -Inf
     )
   }
diff --git a/tests/testthat/test-independent-fixed_design.R b/tests/testthat/test-independent-fixed_design.R
index d8100fac..25794cdf 100644
--- a/tests/testthat/test-independent-fixed_design.R
+++ b/tests/testthat/test-independent-fixed_design.R
@@ -138,7 +138,7 @@ test_that("MaxCombo", {
     tau = c(-1, 4, 6)
   )
 
-  expect_equal(y$analysis$power, 0.9, tolerance = testthat_tolerance() * 100)
+  expect_equal(y$analysis$power, 0.9, tolerance = testthat_tolerance() * 1000)
 })
 
 test_that("RMST", {