diff --git a/rules/preprocessGenomes.smk b/rules/preprocessGenomes.smk
index 5c67eecff86693708842406f1edb9f8b8ae066a3..3b9d80b1d44161498847af0e733128a2f49ab6e0 100644
--- a/rules/preprocessGenomes.smk
+++ b/rules/preprocessGenomes.smk
@@ -17,7 +17,7 @@ rule splitGffPerChrom:
         params: "chr{chrom}"
         shell:  
                 """
-                fgrep  {params} {input} 1> {output} 2> {log}
+                fgrep -i {params} {input} 1> {output} 2> {log}
                 """
 
 rule indexQuery: