diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@
 data Term
   = IncDP        -- >
   | DecDP        -- <
+  | OutDP        -- ?
   | IncByte      -- +
   | DecByte      -- -
   | OutByte      -- .
diff --git a/brainfuck-tut.cabal b/brainfuck-tut.cabal
--- a/brainfuck-tut.cabal
+++ b/brainfuck-tut.cabal
@@ -1,5 +1,5 @@
 name:                brainfuck-tut
-version:             0.6.0.1
+version:             0.7.0.0
 synopsis:            A simple BF interpreter.
 license:             BSD3
 license-file:        LICENSE
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,9 @@
+0.7.0.0
+
+* added support for '?' command
+    * this breaks compatibility with programs that use ? as a comment
+      character
+
 0.6.0.1
 
 * update the changelog
diff --git a/src/Language/Brainfuck/Eval.hs b/src/Language/Brainfuck/Eval.hs
--- a/src/Language/Brainfuck/Eval.hs
+++ b/src/Language/Brainfuck/Eval.hs
@@ -70,6 +70,7 @@
         step tape (o:ops) os pos pc jp jpr = case o of
           IncDP -> step tape ops os (pos+1) (next pc) jp jpr
           DecDP -> step tape ops os (pos-1) (next pc) jp jpr
+          OutDP -> print pos >> step tape ops os pos (next pc) jp jpr
           IncByte -> step (modAt tape pos (+1)) ops os pos (next pc) jp jpr
           DecByte -> step (modAt tape pos (subtract 1)) ops os pos (next pc) jp jpr
           OutByte -> showAt tape pos >> step tape ops os pos (next pc) jp jpr
diff --git a/src/Language/Brainfuck/Parse.hs b/src/Language/Brainfuck/Parse.hs
--- a/src/Language/Brainfuck/Parse.hs
+++ b/src/Language/Brainfuck/Parse.hs
@@ -21,6 +21,7 @@
 parse (x:xs) = case x of
   '>' -> IncDP : parse xs
   '<' -> DecDP : parse xs
+  '?' -> OutDP : parse xs
   '+' -> IncByte : parse xs
   '-' -> DecByte : parse xs
   '.' -> OutByte : parse xs
diff --git a/src/Language/Brainfuck/Types.hs b/src/Language/Brainfuck/Types.hs
--- a/src/Language/Brainfuck/Types.hs
+++ b/src/Language/Brainfuck/Types.hs
@@ -34,6 +34,7 @@
 data Term
   = IncDP        -- ^ \>
   | DecDP        -- ^ <
+  | OutDP        -- ^ ?
   | IncByte      -- ^ +
   | DecByte      -- ^ \-
   | OutByte      -- ^ .