diff --git a/Pmodules/libpmodules.bash.in b/Pmodules/libpmodules.bash.in
index f118b8d..ea15fbc 100644
--- a/Pmodules/libpmodules.bash.in
+++ b/Pmodules/libpmodules.bash.in
@@ -38,18 +38,17 @@ print_help() {
 #       $1: absolute path of a modulefile directory
 #
 compute_group_depth () {
-        local -r dir=$1
+	local -n result="$1"
+        local -r dir="$2"
 	test -d "${dir}" || return 1
         local group=${dir%/*}
         local group=${group##*/}
-        [[ -n "${GroupDepths[${group}]}" ]] && return 0
-	local -i depth=$(${find} "${dir}" -depth \( -type f -o -type l \) \
+	local -i result=$(${find} "${dir}" -depth \( -type f -o -type l \) \
                           -printf "%d" -quit 2>/dev/null)
-	(( depth-=2 ))
+	(( result-=2 ))
 	# if a group doesn't contain a modulefile, depth is negativ
 	# :FIXME: better solution?
-	(( depth < 0 )) && (( depth = 0 ))
-	GroupDepths[$group]=${depth}
+	(( result < 0 )) && (( result = 0 ))
 }
 
 #
@@ -62,9 +61,13 @@ scan_groups () {
         local    ol
         for ol in "$@"; do
 		local mod_root="${OverlayInfo[${ol}:mod_root]}"
+		local -i depth
 	        local dir
 	        for dir in ${mod_root}/*/${PMODULES_MODULEFILES_DIR}; do
-		        compute_group_depth "${dir}"
+			if [[ -n "${GroupDepths[${group}]}" ]]; then
+				compute_group_depth depth "${dir}"
+				GroupDepths[$group]=${depth}
+			fi
 			Dir2OverlayMap[${dir%/${PMODULES_MODULEFILES_DIR}*}]="${ol}"
 	        done
         done
diff --git a/Pmodules/modulecmd.bash.in b/Pmodules/modulecmd.bash.in
index ea7f5c0..42e9471 100644
--- a/Pmodules/modulecmd.bash.in
+++ b/Pmodules/modulecmd.bash.in
@@ -484,7 +484,9 @@ subcommand_load() {
 		local ol=''
 		find_overlay_with_group ol "${group}" || return 1
 		local moduledir="${OverlayInfo[${ol}:mod_root]}/${group}/${PMODULES_MODULEFILES_DIR}"
-		compute_group_depth "${moduledir}" || return 1
+		local -i depth
+		compute_group_depth depth "${moduledir}" || return 1
+		GroupDepths[${group}]=${depth}
 		g_env_must_be_saved='yes'
 	}