diff --git a/mercurial/logcmdutil.py b/mercurial/logcmdutil.py
--- a/mercurial/logcmdutil.py
+++ b/mercurial/logcmdutil.py
@@ -99,6 +99,9 @@
         width = 80
         if not ui.plain():
             width = ui.termwidth() - graphwidth
+        # If an explicit --root was given, don't respect ui.relative-paths
+        if not relroot:
+            pathfn = compose(scmutil.getuipathfn(repo), pathfn)
 
     chunks = ctx2.diff(ctx1, match, changes, opts=diffopts, pathfn=pathfn,
                        copysourcematch=copysourcematch,
diff --git a/tests/test-diffstat.t b/tests/test-diffstat.t
--- a/tests/test-diffstat.t
+++ b/tests/test-diffstat.t
@@ -146,10 +146,21 @@
   $ hg diff --stat .
    dir1/new |  1 +
    1 files changed, 1 insertions(+), 0 deletions(-)
+  $ hg diff --stat . --config ui.relative-paths=yes
+   new |  1 +
+   1 files changed, 1 insertions(+), 0 deletions(-)
   $ hg diff --stat --root .
    new |  1 +
    1 files changed, 1 insertions(+), 0 deletions(-)
 
+  $ hg diff --stat --root . --config ui.relative-paths=yes
+   new |  1 +
+   1 files changed, 1 insertions(+), 0 deletions(-)
+--root trumps ui.relative-paths
+  $ hg diff --stat --root .. --config ui.relative-paths=yes
+   new         |  1 +
+   ../dir2/new |  1 +
+   2 files changed, 2 insertions(+), 0 deletions(-)
   $ hg diff --stat --root ../dir1 ../dir2
   warning: ../dir2 not inside relative root .