diff --git a/configure b/configure
index d0ac29ae1..3c865dad9 100755
--- a/configure
+++ b/configure
@@ -692,13 +692,21 @@ read_registry_file()
 				if [ "${mem}" != "${mems_mem}" ]; then
 
 					#clist="${config_registry[$config]}"
-					clist=$(query_array "config_registry" ${config})
+					clisttmp=$(query_array "config_registry" ${config})
 
 					# Replace the current config with its constituent config set,
 					# canonicalize whitespace, and then remove duplicate config
 					# set names, if they exist. Finally, update the config registry
 					# with the new config list.
-					newclist=$(echo -e "${clist}" | sed -e "s/${mem}/${mems_mem}/g")
+					# NOTE: WE must use substitute_words() rather than a simple sed
+					# expression because we need to avoid matching partial strings.
+					# For example, if clist above contains "foo bar barsk" and we use
+					# sed to substitute "bee boo" as the members of "bar", the
+					# result would (incorrectly) be "foo bee boo bee boosk",
+					# which would then get reduced, via rm_duplicate_words(), to
+					# "foo bee boo boosk".
+					#newclist=$(echo -e "${clist}" | sed -e "s/${mem}/${mems_mem}/g")
+					newclist=$(substitute_words "${mem}" "${mems_mem}" "${clisttmp}")
 					newclist=$(canonicalize_ws "${newclist}")
 					newclist=$(rm_duplicate_words "${newclist}")
 
@@ -781,6 +789,13 @@ read_registry_file()
 					# canonicalize whitespace, and then remove duplicate kernel
 					# set names, if they exist. Finally, update the kernel registry
 					# with the new kernel list.
+					# NOTE: WE must use substitute_words() rather than a simple sed
+					# expression because we need to avoid matching partial strings.
+					# For example, if klist above contains "foo bar barsk" and we use
+					# sed to substitute "bee boo" as the members of "bar", the
+					# result would (incorrectly) be "foo bee boo bee boosk",
+					# which would then get reduced, via rm_duplicate_words(), to
+					# "foo bee boo boosk".
 					#newklist=$(echo -e "${klisttmp}" | sed -e "s/${ker}/${kers_ker}/g")
 					newklist=$(substitute_words "${ker}" "${kers_ker}" "${klisttmp}")
 					newklist=$(canonicalize_ws "${newklist}")