diff --git a/test/exec.bats b/test/exec.bats
index 0e4852f2..ecff7c70 100644
--- a/test/exec.bats
+++ b/test/exec.bats
@@ -2,6 +2,13 @@
 
 load test_helper
 
+create_executable() {
+  bin="${RBENV_ROOT}/versions/${RBENV_VERSION}/bin"
+  mkdir -p "$bin"
+  echo "$2" > "${bin}/$1"
+  chmod +x "${bin}/$1"
+}
+
 @test "supports hook path with spaces" {
   hook_path="${RBENV_TEST_DIR}/custom stuff/rbenv hooks"
   mkdir -p "${hook_path}/exec"
@@ -12,3 +19,41 @@ load test_helper
   assert_success
   assert_line "HELLO=from hook"
 }
+
+@test "forwards all arguments" {
+  export RBENV_VERSION="2.0"
+  create_executable "ruby" "#!$BASH
+    echo \$0
+    while [[ \$# -gt 0 ]]; do
+      # hack to avoid bash builtin echo which can't output '-e'
+      \$(which echo) \$1
+      shift 1
+    done
+    "
+
+  run rbenv-exec ruby -w -e "puts 'hello world'" -- extra args
+  assert_line 0 "${RBENV_ROOT}/versions/2.0/bin/ruby"
+  assert_line 1 "-w"
+  assert_line 2 "-e"
+  assert_line 3 "puts 'hello world'"
+  assert_line 4 "--"
+  assert_line 5 "extra"
+  assert_line 6 "args"
+  refute_line 7
+}
+
+@test "supports ruby -S <cmd>" {
+  export RBENV_VERSION="2.0"
+  create_executable "ruby" "#!$BASH
+    if [[ \$1 = '-S' ]]; then
+      head -1 \$(which \$2) | grep ruby >/dev/null
+      exit \$?
+    else
+      echo 'ruby 2.0 (rbenv test)'
+    fi"
+  create_executable "rake" "#!/usr/bin/env ruby"
+
+  rbenv-rehash
+  run ruby -S rake
+  assert_success
+}
diff --git a/test/test_helper.bash b/test/test_helper.bash
index 85e8853b..5fb24def 100644
--- a/test/test_helper.bash
+++ b/test/test_helper.bash
@@ -62,9 +62,18 @@ assert_line() {
 }
 
 refute_line() {
-  for line in "${lines[@]}"; do
-    if [ "$line" = "$1" ]; then flunk "expected to not find line \`$line'"; fi
-  done
+  if [ "$1" -ge 0 ] 2>/dev/null; then
+    num_lines="${#lines[@]}"
+    if [ "$1" -lt "$num_lines" ]; then
+      flunk "output has $num_lines lines"
+    fi
+  else
+    for line in "${lines[@]}"; do
+      if [ "$line" = "$1" ]; then
+        flunk "expected to not find line \`$line'"
+      fi
+    done
+  fi
 }
 
 assert() {