Due to a recent change in the cider-nrepl API, org-babel integration with Clojure broke. This can be seen here (https://github.com/clojure-emacs/cider/issues/1302) and here (https://github.com/clojure-emacs/cider/issues/1295#issuecomment-137052682). To use the function declaration as an example, this: (declare-function nrepl-sync-request:eval "ext:nrepl-client" (input &optional ns session)) needs to be swapped for this: (declare-function nrepl-sync-request:eval "ext:nrepl-client" (input connection session &optional ns)) As a workaround in the meantime, I modified the nrepl-sync-request:eval call in org-babel-execute:clojure as follows: (nrepl-sync-request:eval expanded (cider-current-connection) (cider-current-session) (cider-current-ns)) That got my system working properly. On a tangential note, I wonder if it might be acceptable to drop the option to use SLIME for Clojure execution. If I'm remembering correctly, I don't believe SLIME is supported by Clojure anymore. All Emacs integration these days goes through CIDER and nREPL. It's likely safe to abandon ob-clojure's SLIME support, at this point. See the first paragraph of the CIDER Github page (https://github.com/clojure-emacs/cider). Thanks, Elliott "Seylerius" Seyler Emacs : GNU Emacs 24.5.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.16.6) of 2015-09-09 on foutrelis Package: Org-mode version 8.3.2 (release_8.3.2-164-g50a182.dirty @ /usr/share/emacs/site-lisp/org/) current state: ============== (setq org-export-backends '(odt md latex icalendar html ascii) org-hide-leading-stars t org-reveal-mathjax t org-tab-first-hook '(org-hide-block-toggle-maybe org-babel-hide-result-toggle-maybe org-babel-header-arg-expand) org-speed-command-hook '(org-speed-command-default-hook org-babel-speed-command-hook) org-occur-hook '(org-first-headline-recenter) org-metaup-hook '(org-babel-load-in-session-maybe) org-html-format-drawer-function '(lambda (name contents) contents) org-log-done t org-latex-format-inlinetask-function 'org-latex-format-inlinetask-default-function org-confirm-shell-link-function 'yes-or-no-p org-ascii-format-inlinetask-function 'org-ascii-format-inlinetask-default org-latex-format-headline-function 'org-latex-format-headline-default-function org-startup-indented t org-after-todo-state-change-hook '(org-clock-out-if-current) org-latex-format-drawer-function '(lambda (name contents) contents) org-odt-format-headline-function 'org-odt-format-headline-default-function org-from-is-user-regexp nil org-src-mode-hook '(org-src-babel-configure-edit-buffer org-src-mode-configure-edit-buffer) org-agenda-before-write-hook '(org-agenda-add-entry-text) org-babel-pre-tangle-hook '(save-buffer) org-trigger-hook '(org-depend-trigger-todo) org-mode-hook '(#[nil "\300\301\302\303\304$\207" [org-add-hook change-major-mode-hook org-show-block-all append local] 5] #[nil "\300\301\302\303\304$\207" [org-add-hook change-major-mode-hook org-babel-show-result-all append local] 5] org-babel-result-hide-spec org-babel-hide-all-hashes org-minor-modes-hook) org-archive-hook '(org-attach-archive-delete-maybe) org-ascii-format-drawer-function '(lambda (name contents width) contents) org-odt-format-inlinetask-function 'org-odt-format-inlinetask-default-function org-ctrl-c-ctrl-c-hook '(org-babel-hash-at-point org-babel-execute-safely-maybe) org-enforce-todo-dependencies t org-cycle-hook '(org-cycle-hide-archived-subtrees org-cycle-hide-drawers org-cycle-show-empty-lines org-optimize-window-after-visibility-change) org-reveal-mathjax-url "file:///home/emhs/MathJax/MathJax.js" org-babel-tangle-lang-exts '(("clojure" . "clj") ("emacs-lisp" . "el") ("elisp" . "el")) org-confirm-elisp-link-function 'yes-or-no-p org-metadown-hook '(org-babel-pop-to-session-maybe) org-odt-format-drawer-function '(lambda (name contents) contents) org-blocker-hook '(org-block-todo-from-children-or-siblings-or-parent org-depend-block-todo) org-html-format-headline-function 'org-html-format-headline-default-function org-html-format-inlinetask-function 'org-html-format-inlinetask-default-function org-clock-out-hook '(org-clock-remove-empty-clock-drawer) )