diff --git a/main.nf b/main.nf
index 10a1b954e56117a3d0d30636e22f9501ec3dd762..565dbf19bcdc80620010617520070d8001884bdc 100644
--- a/main.nf
+++ b/main.nf
@@ -181,9 +181,9 @@ if ( params.bwt2_index ){
 
 }
 else if ( params.fasta ) {
-    lastPath = params.fasta.lastIndexOf(File.separator)
-    fasta_base = params.fasta.substring(lastPath+1)
-    bwt2_base = fasta_base.toString() - ~/(\.fa)?(\.fasta)?(\.fas)?(\.fsa)?$/
+   lastPath = params.fasta.lastIndexOf(File.separator)
+   fasta_base = params.fasta.substring(lastPath+1)
+   bwt2_base = fasta_base.toString() - ~/(\.fa)?(\.fasta)?(\.fas)?(\.fsa)?$/
  
    Channel.fromPath( params.fasta )
 	.ifEmpty { exit 1, "Genome index: Fasta file not found: ${params.fasta}" }