diff --git a/DAMASK_env.sh b/DAMASK_env.sh
index d9b5b004f..da033afbe 100644
--- a/DAMASK_env.sh
+++ b/DAMASK_env.sh
@@ -71,11 +71,19 @@ if [ ! -z "$PS1" ]; then
   echo -n "heap  size         "
    [[ "$(ulimit -d)" == "unlimited" ]] \
    && echo "unlimited" \
-   || echo $(python -c "import math; size=$(( 1024*$(ulimit -d) )); print '{:.4g} {}'.format(size / (1 << ((int(math.log(size,2) / 10) if size else 0) * 10)), ['bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'EiB', 'ZiB'][int(math.log(size,2) / 10) if size else 0])")
+   || echo $(python -c \
+          "import math; \
+           size=$(( 1024*$(ulimit -d) )); \
+           print '{:.4g} {}'.format(size / (1 << ((int(math.log(size,2) / 10) if size else 0) * 10)), \
+           ['bytes','KiB','MiB','GiB','TiB','EiB','ZiB'][int(math.log(size,2) / 10) if size else 0])")
   echo -n "stack size         "
    [[ "$(ulimit -s)" == "unlimited" ]] \
    && echo "unlimited" \
-   || echo $(python -c "import math; size=$(( 1024*$(ulimit -s) )); print '{:.4g} {}'.format(size / (1 << ((int(math.log(size,2) / 10) if size else 0) * 10)), ['bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'EiB', 'ZiB'][int(math.log(size,2) / 10) if size else 0])")
+   || echo $(python -c \
+          "import math; \
+           size=$(( 1024*$(ulimit -s) )); \
+           print '{:.4g} {}'.format(size / (1 << ((int(math.log(size,2) / 10) if size else 0) * 10)), \
+           ['bytes','KiB','MiB','GiB','TiB','EiB','ZiB'][int(math.log(size,2) / 10) if size else 0])")
 fi
 
 export DAMASK_NUM_THREADS
diff --git a/DAMASK_env.zsh b/DAMASK_env.zsh
index 082fa8007..fa9a33987 100644
--- a/DAMASK_env.zsh
+++ b/DAMASK_env.zsh
@@ -59,11 +59,19 @@ if [ ! -z "$PS1" ]; then
   echo -n "heap  size         "
    [[ "$(ulimit -d)" == "unlimited" ]] \
    && echo "unlimited" \
-   || echo $(python -c "import math; size=$(( 1024*$(ulimit -d) )); print '{:.4g} {}'.format(size / (1 << ((int(math.log(size,2) / 10) if size else 0) * 10)), ['bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'EiB', 'ZiB'][int(math.log(size,2) / 10) if size else 0])")
+   || echo $(python -c \
+          "import math; \
+           size=$(( 1024*$(ulimit -d) )); \
+           print '{:.4g} {}'.format(size / (1 << ((int(math.log(size,2) / 10) if size else 0) * 10)), \
+           ['bytes','KiB','MiB','GiB','TiB','EiB','ZiB'][int(math.log(size,2) / 10) if size else 0])")
   echo -n "stack size         "
    [[ "$(ulimit -s)" == "unlimited" ]] \
    && echo "unlimited" \
-   || echo $(python -c "import math; size=$(( 1024*$(ulimit -s) )); print '{:.4g} {}'.format(size / (1 << ((int(math.log(size,2) / 10) if size else 0) * 10)), ['bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'EiB', 'ZiB'][int(math.log(size,2) / 10) if size else 0])")
+   || echo $(python -c \
+          "import math; \
+           size=$(( 1024*$(ulimit -s) )); \
+           print '{:.4g} {}'.format(size / (1 << ((int(math.log(size,2) / 10) if size else 0) * 10)), \
+           ['bytes','KiB','MiB','GiB','TiB','EiB','ZiB'][int(math.log(size,2) / 10) if size else 0])")
 fi
 
 export DAMASK_NUM_THREADS