diff --git a/src/nf_modules/Kallisto/kallisto.nf b/src/nf_modules/Kallisto/kallisto.nf
index 8867a0c3ab74393a43229e9bee4a39e71f4eddc2..cd7b1ea43bc30af102f08283201f33e6bf3a759a 100644
--- a/src/nf_modules/Kallisto/kallisto.nf
+++ b/src/nf_modules/Kallisto/kallisto.nf
@@ -59,7 +59,7 @@ process mapping_fastq {
 
   input:
   set pair_id, file(reads) from fastq_files
-  file index from index_files.toList()
+  file index from index_files.collect()
 
   output:
   file "*" into counts_files
@@ -104,7 +104,7 @@ process mapping_fastq {
 
   input:
   file reads from fastq_files
-  file index from index_files.toList()
+  file index from index_files.collect()
 
   output:
   file "*" into count_files
diff --git a/src/nf_modules/Kallisto/tests/mapping_paired.nf b/src/nf_modules/Kallisto/tests/mapping_paired.nf
index 8e8f94c9172c409a5af3be0be02f3970e5983030..15718373d0372803b78e316edec6f3e39343a0b1 100644
--- a/src/nf_modules/Kallisto/tests/mapping_paired.nf
+++ b/src/nf_modules/Kallisto/tests/mapping_paired.nf
@@ -20,7 +20,7 @@ process mapping_fastq {
 
   input:
   set pair_id, file(reads) from fastq_files
-  file index from index_files.toList()
+  file index from index_files.collect()
 
   output:
   file "*" into counts_files
diff --git a/src/nf_modules/Kallisto/tests/mapping_single.nf b/src/nf_modules/Kallisto/tests/mapping_single.nf
index 2a46cbe6dc1274a2c46044f01a54e43c981126ad..69e3a6fdcafe5d1804a96cd482f6b5ff4cf50bfe 100644
--- a/src/nf_modules/Kallisto/tests/mapping_single.nf
+++ b/src/nf_modules/Kallisto/tests/mapping_single.nf
@@ -24,7 +24,7 @@ process mapping_fastq {
 
   input:
   file reads from fastq_files
-  file index from index_files.toList()
+  file index from index_files.collect()
 
   output:
   file "*" into count_files