Verify and clarify that vterm needs module supportemacs_module_support

Fixes #113

2 files changed, 8 insertions, 2 deletions

diff --git a/README.md b/README.md
index 00107b4..8c3f322 100644
--- a/README.md
+++ b/README.md
@@ -20,8 +20,11 @@ git clone https://github.com/akermu/emacs-libvterm.git
 
 Before installing emacs-libvterm, you need to make sure you have
 installed
- 1. cmake (>=3.11)
- 2. libtool-bin (related issues: [#66](https://github.com/akermu/emacs-libvterm/issues/66) [#85](https://github.com/akermu/emacs-libvterm/issues/85#issuecomment-491845136))
+ 1. Emacs with [module
+    support](https://www.gnu.org/software/emacs/manual/html_node/elisp/Dynamic-Modules.html).
+    You can check that, by verifying that `module-file-suffix` is not `nil`.
+ 2. cmake (>=3.11)
+ 3. libtool-bin (related issues: [#66](https://github.com/akermu/emacs-libvterm/issues/66) [#85](https://github.com/akermu/emacs-libvterm/issues/85#issuecomment-491845136))
 
 Run the build:
 
diff --git a/vterm.el b/vterm.el
index eb30382..2149fc7 100644
--- a/vterm.el
+++ b/vterm.el
@@ -42,6 +42,9 @@
 
 ;;; Code:
 
+(unless module-file-suffix
+  (error "VTerm needs module support. Please compile your Emacs with the --with-modules option!"))
+
 (require 'term)
 
 (defvar vterm-install-buffer-name " *Install vterm"