diff --git a/README.md b/README.md
index 2ae86d9..9325878 100644
--- a/README.md
+++ b/README.md
@@ -59,5 +59,5 @@ Next, transfer the bbtools.sif file to the system on which you want to run BBToo
 BBTOOLS_SIF=path/to/bbtools39.01.sif
 
 # Test that BBTools can run from Singularity container
-singularity run $BBTOOLS_SIF bbduk.sh --help # depending on system/version, singularity may be called apptainer
+singularity run $BBTOOLS_SIF bbduk.sh -Xmx500m --version # depending on system/version, singularity may be called apptainer
 ```
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