diff --git a/test/stub.sh b/test/stub.sh
new file mode 100644
index 0000000..e262fdb
--- /dev/null
+++ b/test/stub.sh
@@ -0,0 +1,35 @@
+# Stub commands for testing purposes.
+#
+# Arguments:
+#   - $1: Name of command to stub.
+#   - $2: Output will go to STDERR when $2 is "STDERR".
+#
+stub() {
+  local cmd="$1"
+  if [ "$2" == "STDERR" ]; then local redirect=" 1>&2"; fi
+
+  if [[ "$(type "$cmd" | head -1)" == *"is a function" ]]; then
+    local source="$(type "$cmd" | tail -n +2)"
+    source="${source/$cmd/non_stubbed_${cmd}}"
+    eval "$source"
+  fi
+  eval "$(echo -e "${1}() {\n  echo \"$1 stub: \$@\"$redirect\n}")"
+}
+
+# Restore the original command/function that was stubbed with stub().
+#
+# Arguments:
+#   - $1: Name of command to restore.
+#
+restore() {
+  local cmd="$1"
+  unset -f "$cmd"
+  if type "non_stubbed_${cmd}" &>/dev/null; then
+    if [[ "$(type "non_stubbed_${cmd}" | head -1)" == *"is a function" ]]; then
+      local source="$(type "non_stubbed_$cmd" | tail -n +2)"
+      source="${source/non_stubbed_${cmd}/$cmd}"
+      eval "$source"
+      unset -f "non_stubbed_${cmd}"
+    fi
+  fi
+}
diff --git a/test/test-helper.sh b/test/test-helper.sh
index 085f44a..f435b12 100644
--- a/test/test-helper.sh
+++ b/test/test-helper.sh
@@ -3,6 +3,7 @@ testroot="$(dirname "$BASH_SOURCE")"
 
 # Include assert.sh testing library.
 source "$testroot/assert.sh"
+source "$testroot/stub.sh"
 
 #
 # Additional test helpers.
@@ -12,30 +13,3 @@ source "$testroot/assert.sh"
 cd-back() {
   cd - 1>/dev/null
 }
-
-# Stub commands printing it's name and arguments to STDOUT or STDERR.
-stub() {
-  local cmd="$1"
-  if [ "$2" == "STDERR" ]; then local redirect=" 1>&2"; fi
-
-  if [[ "$(type "$cmd" | head -1)" == *"is a function" ]]; then
-    local source="$(type "$cmd" | tail -n +2)"
-    source="${source/$cmd/original_${cmd}}"
-    eval "$source"
-  fi
-  eval "$(echo -e "${1}() {\n  echo \"$1 stub: \$@\"$redirect\n}")"
-}
-
-# Restore the original command/function that was stubbed with stub.
-restore() {
-  local cmd="$1"
-  unset -f "$cmd"
-  if type "original_${cmd}" &>/dev/null; then
-    if [[ "$(type "original_${cmd}" | head -1)" == *"is a function" ]]; then
-      local source="$(type "original_$cmd" | tail -n +2)"
-      source="${source/original_${cmd}/$cmd}"
-      eval "$source"
-      unset -f "original_${cmd}"
-    fi
-  fi
-}