diff --git a/lib/spack/spack/cmd/spec.py b/lib/spack/spack/cmd/spec.py
index 4dd4474bd4d393eaf8ff7bf2e3241bdc1474af77..4ecd4d6e549d31f785123c4de703ba5e8c33099e 100644
--- a/lib/spack/spack/cmd/spec.py
+++ b/lib/spack/spack/cmd/spec.py
@@ -48,6 +48,9 @@ def setup_parser(subparser):
         help='Show install status of packages.  Packages can be: '
              'installed [+], missing and needed by an installed package [-], '
              'or not installed (no annotation).')
+    subparser.add_argument(
+        '-t', '--types', action='store_true', default=False,
+        help='Show dependency types.')
     subparser.add_argument(
         'specs', nargs=argparse.REMAINDER, help="specs of packages")
 
@@ -59,6 +62,7 @@ def spec(parser, args):
               'format': name_fmt + '$@$%@+$+$=',
               'hashes': args.long or args.very_long,
               'hashlen': None if args.very_long else 7,
+              'show_types': args.types,
               'install_status': args.install_status}
 
     for spec in spack.cmd.parse_specs(args.specs):
diff --git a/lib/spack/spack/spec.py b/lib/spack/spack/spec.py
index 23212ba72b2ef369567cd856d855b3cf9011a791..8230142d4396c3653fde56b058efecb4d1f92007 100644
--- a/lib/spack/spack/spec.py
+++ b/lib/spack/spack/spec.py
@@ -2595,17 +2595,22 @@ def tree(self, **kwargs):
         indent = kwargs.pop('indent', 0)
         fmt = kwargs.pop('format', '$_$@$%@+$+$=')
         prefix = kwargs.pop('prefix', None)
+        show_types = kwargs.pop('show_types', False)
         deptypes = kwargs.pop('deptypes', ('build', 'link'))
         check_kwargs(kwargs, self.tree)
 
         out = ""
-        for d, node in self.traverse(
+        for d, dep_spec in self.traverse_with_deptype(
                 order='pre', cover=cover, depth=True, deptypes=deptypes):
+            node = dep_spec.spec
+
             if prefix is not None:
                 out += prefix(node)
             out += " " * indent
+
             if depth:
                 out += "%-4d" % d
+
             if install_status:
                 status = node._install_status()
                 if status is None:
@@ -2617,6 +2622,16 @@ def tree(self, **kwargs):
 
             if hashes:
                 out += colorize('@K{%s}  ', color=color) % node.dag_hash(hlen)
+
+            if show_types:
+                out += '['
+                if dep_spec.deptypes:
+                    for t in alldeps:
+                        out += ''.join(t[0] if t in dep_spec.deptypes else ' ')
+                else:
+                    out += ' ' * len(alldeps)
+                out += ']  '
+
             out += ("    " * d)
             if d > 0:
                 out += "^"