diff --git a/README.md b/README.md
index 84e61c7..74c9a0a 100755
--- a/README.md
+++ b/README.md
@@ -29,7 +29,7 @@ N.B. For sunbeam versions <4 the last command will be something like `sunbeam ru
 
 ## Configuration
 
-  - genomes_fp: Is the filepath to your reference genomes (in fasta format) **references must have .fasta extension!!**
+  - genomes_fp: Is the filepath to your reference genomes (in fasta format) **all references must have .fasta OR .fa OR .fna extension!!**
   - samtools_opts: Are the options passed to samtools view
   - alnLen: Is the minimum alignment length
   - percIdentity: Is the minimum percent identity