diff --git a/nvm.sh b/nvm.sh
index db16abe7..58f2704d 100755
--- a/nvm.sh
+++ b/nvm.sh
@@ -3294,7 +3294,9 @@ nvm_print_implicit_alias() {
   esac
   local MINOR
   local STABLE
+  STABLE=''
   local UNSTABLE
+  UNSTABLE=''
   local MOD
   local NORMALIZED_VERSION
 
diff --git a/test/fast/Listing versions/Running 'nvm ls' with nounset should not fail b/test/fast/Listing versions/Running 'nvm ls' with nounset should not fail
index f6770917..90f0851d 100755
--- a/test/fast/Listing versions/Running 'nvm ls' with nounset should not fail	
+++ b/test/fast/Listing versions/Running 'nvm ls' with nounset should not fail	
@@ -6,19 +6,29 @@ die () { echo "$@" ; exit 1; }
 \. ../../../nvm.sh
 \. ../../common.sh
 
-make_fake_node v0.12.34 || die 'fake v0.12.34 could not be made'
-
 # Enable no unset variable
 set -u
 
+# Nothing is installed, so there is no stable version to resolve to
+output=$(nvm ls 2>&1 1>/dev/null || true)
+test -z "${output}" || die "1: expected empty; got >${output}"
+
+make_fake_node v0.11.16 || die 'fake v0.11.16 could not be made'
+
+# Only an unstable version is installed, so `stable` still has nothing to resolve to
+output=$(nvm ls 2>&1 1>/dev/null || true)
+test -z "${output}" || die "2: expected empty; got >${output}"
+
+make_fake_node v0.12.34 || die 'fake v0.12.34 could not be made'
+
 # Try an alias that does not exist
 output=$(nvm ls 99 2>&1 1>/dev/null || true)
-test -z "${output}" || die "1: expected empty; got >${output}"
+test -z "${output}" || die "3: expected empty; got >${output}"
 
 # Try a version that does not exist
 output=$(nvm ls 0.12.00 2>&1 1>/dev/null || true)
-test -z "${output}" || die "2: expected empty; got >${output}"
+test -z "${output}" || die "4: expected empty; got >${output}"
 
 # Try a version that does exist
 output=$(nvm ls 0.12.34 2>&1 1>/dev/null || true)
-test -z "${output}" || die "3: expected empty; got >${output}"
+test -z "${output}" || die "5: expected empty; got >${output}"
diff --git a/test/fast/Unit tests/nvm commands ignore option variables set by the caller b/test/fast/Unit tests/nvm commands ignore option variables set by the caller
index 08acd927..517e9daf 100755
--- a/test/fast/Unit tests/nvm commands ignore option variables set by the caller	
+++ b/test/fast/Unit tests/nvm commands ignore option variables set by the caller	
@@ -54,4 +54,19 @@ VERSION=v20.0.0
 [ $? = 127 ] || die 'nvm use without a version or an .nvmrc should fail, rather than use an outer VERSION'
 unset VERSION
 
+# with nothing installed, `nvm ls stable` has no version to resolve to, so an outer STABLE must not supply one
+NVM_DIR="${TMP_DIR}/empty"
+mkdir -p "${NVM_DIR}"
+OUTPUT="$(nvm ls stable | tr -d ' \n')"
+STABLE=v20.0.0
+OUTPUT_WITH_STABLE="$(nvm ls stable | tr -d ' \n')"
+[ "_${OUTPUT_WITH_STABLE}" = "_${OUTPUT}" ] || die "nvm ls stable should ignore an outer STABLE; got >${OUTPUT_WITH_STABLE}< instead of >${OUTPUT}<"
+unset STABLE
+
+# likewise for an outer UNSTABLE; `nvm ls unstable` can't show it, since the leaked version isn't installed either
+UNSTABLE=v21.0.0
+OUTPUT="$(nvm_print_implicit_alias local unstable)"
+[ "_${OUTPUT}" = '_N/A' ] || die "nvm_print_implicit_alias local unstable should ignore an outer UNSTABLE; got >${OUTPUT}<"
+unset UNSTABLE
+
 cleanup