diff --git a/R/utils_group_comparison.R b/R/utils_group_comparison.R
index ef2d384..355cabd 100644
--- a/R/utils_group_comparison.R
+++ b/R/utils_group_comparison.R
@@ -417,8 +417,8 @@ fit_Group_Sub_model = function(data) {
 #' @return a contrast vector
 .makeContrastSingleTMT = function(fit, contrast, single_protein, coefs) {
   sub_groups = as.character(unique(single_protein$Group))
-  positive = names(contrast)[contrast > 0]
-  negative = names(contrast)[contrast < 0]
+  positive = colnames(contrast)[contrast > 0]
+  negative = colnames(contrast)[contrast < 0]
   
   if (!(all(positive %in% sub_groups) & all(negative %in% sub_groups))) {
     contrast_updated = unname(contrast[, sub_groups])
@@ -471,4 +471,4 @@ fit_Group_Sub_model = function(data) {
   new_values = new_values * abs(1 / sum(new_values, na.rm = TRUE))
   contrast[condition] = new_values
   contrast
-}
\ No newline at end of file
+}