diff --git a/elisp/shm-ast.el b/elisp/shm-ast.el
--- a/elisp/shm-ast.el
+++ b/elisp/shm-ast.el
@@ -331,11 +331,10 @@
                                 (line-end-position))))
                ;; Don't activate if we're doing a GHCi command.
                (unless (and (string-match "^:" whole-line)
-                            (not (string-match "^:t[^ ]* " whole-line))
-                            (not (string-match "^:k[^ ]* " whole-line)))
+                            (not (string-match "^:[tk] " whole-line)))
                  (cons (save-excursion
                          (goto-char haskell-interactive-mode-prompt-start)
-                         (when (looking-at ":[kt][^ ]* ")
+                         (when (looking-at ":[kt] ")
                            (search-forward " " (point-max) t 1))
                          (point))
                        (line-end-position))))))))))
diff --git a/structured-haskell-mode.cabal b/structured-haskell-mode.cabal
--- a/structured-haskell-mode.cabal
+++ b/structured-haskell-mode.cabal
@@ -1,5 +1,5 @@
 name:                structured-haskell-mode
-version:             1.0.11
+version:             1.0.12
 synopsis:            Structured editing Emacs mode for Haskell
 description:         Structured editing Emacs mode for Haskell.
 homepage:            https://github.com/chrisdone/structured-haskell-mode
@@ -44,4 +44,4 @@
   build-depends:     base >= 4 && < 5
                    , haskell-src-exts == 1.15.*
                    , text
-                   , descriptive == 0.4.*
+                   , descriptive >= 0.4 && < 0.6