diff --git a/libexec/pyenv-prefix b/libexec/pyenv-prefix
index 1ee317bb..80c033a8 100755
--- a/libexec/pyenv-prefix
+++ b/libexec/pyenv-prefix
@@ -26,7 +26,7 @@ fi
 PYENV_PREFIX_PATHS=()
 for version in "${versions[@]}"; do
   if [ "$version" = "system" ]; then
-    PYTHON_PATH="$(pyenv-which python || true)"
+    PYTHON_PATH="$(PYENV_VERSION="${version}" pyenv-which python || true)"
     PYENV_PREFIX_PATH="${PYTHON_PATH%/*}"
   else
     PYENV_PREFIX_PATH="${PYENV_ROOT}/versions/${version}"