diff --git a/tests/script/tsim/parser/groupby.sim b/tests/script/tsim/parser/groupby.sim
index 12a698b1cc..4ee9c530a7 100644
--- a/tests/script/tsim/parser/groupby.sim
+++ b/tests/script/tsim/parser/groupby.sim
@@ -557,7 +557,7 @@ if $data10 != @{slop:0.000000, intercept:1.000000}@ then
   return -1
 endi
 
-if $data90 != @{slop:0.000000, intercept:9.000000}@ then
+if $data90 != @{slop:0.000000, intercept:17.000000}@ then
   return -1
 endi