diff --git a/Pmodules/modulecmd.bash.in b/Pmodules/modulecmd.bash.in
index 624e7da..ca4c143 100644
--- a/Pmodules/modulecmd.bash.in
+++ b/Pmodules/modulecmd.bash.in
@@ -77,7 +77,10 @@ export_env() {
 	done
 }
 
+declare g_env_must_be_saved='no'
+
 save_env() {
+        [[ ${g_env_must_be_saved} == 'no' ]] && return 0
 	local -r shell="$1"
 	shift
 	local s=''
@@ -497,6 +500,7 @@ subcommand_load() {
                                         std::die 3 "%s %s: illegal release name -- %s\n" \
                                                  "${CMD}" 'load' "${release}"
 				std::append_path UsedReleases "${release}"
+                                g_env_must_be_saved='yes'
 			fi
 		fi
 		local found=''
@@ -967,7 +971,8 @@ get_group_depth () {
         # We set it to 0 (even this might be wrong).
 	# :FIXME: better solution?
 	(( depth < 0 )) && (( depth = 0 ))
-	GroupDepths[$group]=${depth} 
+	GroupDepths[$group]=${depth}
+        g_env_must_be_saved='yes'
 }
 
 #
@@ -1125,8 +1130,10 @@ subcommand_use() {
 			if is_release "${arg}"; then
 			        # releases are always *appended*
 			        std::append_path UsedReleases "${arg}"
+                                g_env_must_be_saved='yes'
 			elif [[ "${arg}" =~ "flag=" ]]; then
 				std::append_path UseFlags "${arg/flag=}"
+                                g_env_must_be_saved='yes'
 			elif [[ "${arg}" =~ "overlay=" ]]; then
                                 local overlay="${arg/overlay=}"
                                 [[ -d "${overlay}" ]] || \
@@ -1142,6 +1149,7 @@ subcommand_use() {
                                                         std::prepend_path MODULEPATH "${dir}"
                                                 fi
                                         done
+                                        g_env_must_be_saved='yes'
                                 fi
                                 
 			elif [[ ! ${arg} =~ */* ]] && is_group "${arg}"; then
@@ -1150,6 +1158,7 @@ subcommand_use() {
                                                  "${CMD}" "${FUNCNAME[0]##*_}" "${arg}"
 				fi
 				std::append_path UsedGroups "${arg}"
+                                g_env_must_be_saved='yes'
                                 for overlay in "${!Overlays[@]}"; do
                                         for group in ${UsedGroups//:/ }; do
                                                 local dir="${overlay}/"
@@ -1171,7 +1180,7 @@ subcommand_use() {
 			shift
 		done
 
-		export_env ${g_shell} MODULEPATH UsedGroups
+		export_env ${g_shell} MODULEPATH
 	}
 
 	local -a args=()
@@ -1252,7 +1261,8 @@ subcommand_unuse() {
             
 		elif [[ "${arg}" =~ "flag=" ]]; then
 			std::remove_path UseFlags "${arg/flag=}"
-
+                        g_env_must_be_saved='yes'
+                        
                 elif [[ "${arg}" =~ "overlay=" ]]; then
                                 local overlay="${arg/overlay=}"
                                 [[ -d "${overlay}" ]] || \
@@ -1272,6 +1282,7 @@ subcommand_unuse() {
                                                         std::remove_path MODULEPATH "${dir}"
                                                 fi
                                         done
+                                        g_env_must_be_saved='yes'
                                 fi
 
 		elif [[ ! ${arg} =~ */* ]] &&  [[ -d ${modulefiles_dir} ]]; then
@@ -1282,27 +1293,24 @@ subcommand_unuse() {
                                          "${arg}"
 			fi
 			std::remove_path UsedGroups "${arg}"
-			dirs_to_remove+=( ${modulefiles_dir} )
-                       
+                        g_env_must_be_saved='yes'
+			std::remove_path MODULEPATH "${modulefiles_dir}"
+
 		elif [[ -d ${arg} ]]; then
 			local normalized_dir=$(cd "${arg}" && pwd)
-			dirs_to_remove+=( ${normalized_dir} )
+                        std::remove_path MODULEPATH "${normalized_dir}"
+
 		elif [[ ${arg} =~ ^${PMODULES_ROOT} ]]; then
 			std::die 3 "%s %s: illegal directory -- %s\n." \
                                  "${CMD}" "${FUNCNAME[0]##*_}" "${arg}"
+
 		else
 			std::die 3 "%s %s: not a directory -- %s\n" \
                                  "${CMD}" "${FUNCNAME[0]##*_}" "${arg}"
 		fi
 		shift
 	done
-
-	declare -g UsedGroups
-	export_env ${g_shell} UsedGroups
-	[[ ${#dirs_to_remove[@]} == 0 ]] && return
-	for dir in "${dirs_to_remove[@]}"; do
-                "${modulecmd}" "${g_shell}" "${subcommand}" "${dir}"
-	done
+        export_env "${g_shell}" 'MODULEPATH'
 }
 
 ##############################################################################
@@ -1360,6 +1368,7 @@ reset_used_groups() {
         for group in ${PMODULES_DEFAULT_GROUPS}; do
                 std::append_path UsedGroups "${group}"
         done
+        g_env_must_be_saved='yes'
 }
 
 reset_used_releases() {
@@ -1367,6 +1376,7 @@ reset_used_releases() {
 	for r in ${PMODULES_DEFAULT_RELEASES//:/ }; do
 		std::append_path UsedReleases "${r}"
 	done
+        g_env_must_be_saved='yes'
 }
 
 init_path() {
@@ -1451,7 +1461,7 @@ subcommand_purge() {
 	"${modulecmd}" "${g_shell}" "${subcommand}"
         reset_modulepath
         reset_used_groups
-	export_env ${g_shell} MODULEPATH UsedGroups
+	export_env ${g_shell} MODULEPATH
 }
 
 ##############################################################################