diff --git a/CHANGELOG.md b/CHANGELOG.md
index 22d08590..c51d50d7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@
 
 ### Bugs fixed
 
+* [#551](https://github.com/clojure-emacs/clojure-mode/issues/551): Indent `clojure-align` region before aligning.
 * [#520](https://github.com/clojure-emacs/clojure-mode/issues/508): Fix allow `clojure-align-cond-forms` to recognize qualified forms.
 * Enhance add arity refactoring to support a defn inside a reader conditional.
 * [#404](https://github.com/clojure-emacs/clojure-mode/issues/404)/[#528]((https://github.com/clojure-emacs/clojure-mode/issues/528)) Fix syntax highlighting for multiple consecutive comment reader macros (`#_#_`)
diff --git a/clojure-mode.el b/clojure-mode.el
index bf183fbe..07127a3f 100644
--- a/clojure-mode.el
+++ b/clojure-mode.el
@@ -1268,15 +1268,16 @@ When called from lisp code align everything between BEG and END."
         (save-excursion
           (while (search-forward-regexp "^ *\n" sexp-end 'noerror)
             (cl-incf count)))
+        ;; Pre-indent the region to avoid aligning to improperly indented
+        ;; contents (#551). Also fixes #360.
+        (indent-region (point) sexp-end)
         (dotimes (_ count)
           (align-region (point) sexp-end nil
                         `((clojure-align (regexp . clojure--search-whitespace-after-next-sexp)
                                          (group . 1)
                                          (separate . ,clojure-align-separator)
                                          (repeat . t)))
-                        nil))
-        ;; Reindent after aligning because of #360.
-        (indent-region (point) sexp-end)))))
+                        nil))))))
 
 ;;; Indentation
 (defun clojure-indent-region (beg end)
diff --git a/test/clojure-mode-indentation-test.el b/test/clojure-mode-indentation-test.el
index 006d6f78..a7075b06 100644
--- a/test/clojure-mode-indentation-test.el
+++ b/test/clojure-mode-indentation-test.el
@@ -659,6 +659,13 @@ x
     "#?@(:clj  [2]
     :cljs [2])")
 
+  (it "should handle improperly indented content"
+    (let ((content "(let [a-long-name 10\nb 20])")
+          (aligned-content "(let [a-long-name 10\n      b           20])"))
+      (with-clojure-buffer content
+        (call-interactively #'clojure-align)
+        (expect (buffer-string) :to-equal aligned-content))))
+
   (it "should not align reader conditionals by default"
     (let ((content "#?(:clj 2\n   :cljs 2)"))
       (with-clojure-buffer content