diff --git a/libexec/rbenv-which b/libexec/rbenv-which
index 6b0d93a2..f656537d 100755
--- a/libexec/rbenv-which
+++ b/libexec/rbenv-which
@@ -15,6 +15,16 @@ if [ "$1" = "--complete" ]; then
   exec rbenv shims --short
 fi
 
+remove_from_path() {
+  local path_to_remove="$1"
+  local path_before
+  local result=":$PATH:"
+  while [ "$path_before" != "$result" ]; do
+    path_before="$result"
+    result="${result//:$path_to_remove:/:}"
+  done
+  echo "${result%:}"
+}
 
 RBENV_COMMAND="$1"
 
@@ -26,18 +36,8 @@ fi
 RBENV_VERSION="${RBENV_VERSION:-$(rbenv-version-name)}"
 
 if [ "$RBENV_VERSION" = "system" ]; then
-  # Remove shims from PATH. Use a loop, because Bash won't remove all ":foo:"
-  # in ":foo:foo:" in one go.
-  path=":$PATH:"
-  remove="${RBENV_ROOT}/shims"
-  while true; do
-    path_before="$path"
-    path="${path//:$remove:/:}"
-    if [[ "$path_before" = "$path" ]]; then
-      break
-    fi
-  done
-  RBENV_COMMAND_PATH="$(PATH=$path command -v "$RBENV_COMMAND" || true)"
+  PATH="$(remove_from_path "${RBENV_ROOT}/shims")"
+  RBENV_COMMAND_PATH="$(command -v "$RBENV_COMMAND" || true)"
 else
   RBENV_COMMAND_PATH="${RBENV_ROOT}/versions/${RBENV_VERSION}/bin/${RBENV_COMMAND}"
 fi