diff --git a/CHANGELOG.md b/CHANGELOG.md
index f0ad026f..56ae7a29 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -32,6 +32,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - [#800](https://github.com/nf-core/ampliseq/pull/800) - Fixed SH files for UNITE9.0, they were missing some entries due to a bug caused by API update in PlutoF
 - [#808](https://github.com/nf-core/ampliseq/pull/808) - Add missing library declaration in R script.
+- [#832](https://github.com/nf-core/ampliseq/pull/832) - Add pattern to input field
 
 ### `Dependencies`
 
diff --git a/nextflow_schema.json b/nextflow_schema.json
index 824f8eba..5cffd9fa 100644
--- a/nextflow_schema.json
+++ b/nextflow_schema.json
@@ -15,6 +15,7 @@
                     "type": "string",
                     "format": "file-path",
                     "mimetype": "text/tsv",
+                    "pattern": "^\\S+\\.(tsv|csv|yml|yaml|txt)$",
                     "fa_icon": "fas fa-dna",
                     "description": "Path to tab-separated sample sheet",
                     "help_text": "Path to sample sheet, either tab-separated (.tsv), comma-separated (.csv), or in YAML format (.yml/.yaml), that points to compressed fastq files.\n\nThe sample sheet must have two to four tab-separated columns/entries with the following headers: \n- `sampleID` (required): Unique sample IDs, must start with a letter, and can only contain letters, numbers or underscores\n- `forwardReads` (required): Paths to (forward) reads zipped FastQ files\n- `reverseReads` (optional): Paths to reverse reads zipped FastQ files, required if the data is paired-end\n- `run` (optional): If the data was produced by multiple sequencing runs, any string\n\nRelated parameters are:\n- `--pacbio` and `--iontorrent` if the sequencing data is PacBio data or IonTorrent data (default expected: paired-end Illumina data)\n- `--single_end` if the sequencing data is single-ended Illumina data (default expected: paired-end Illumina data)\n- Choose an appropriate reference taxonomy for the type of amplicon (16S/18S/ITS/CO1) (default: DADA2 assignTaxonomy and 16S rRNA sequence database)",