diff --git a/hledger-lib/Hledger/Reports/PostingsReport.hs b/hledger-lib/Hledger/Reports/PostingsReport.hs
index 1a93f09b6..1e0a85f54 100644
--- a/hledger-lib/Hledger/Reports/PostingsReport.hs
+++ b/hledger-lib/Hledger/Reports/PostingsReport.hs
@@ -116,7 +116,8 @@ matchedPostingsBeforeAndDuring opts q j (DateSpan mstart mend) =
   where
     beforestartq = dbg1 "beforestartq" $ dateqtype $ DateSpan Nothing mstart
     beforeandduringps =
-      dbg1 "ps4" $ sortBy (comparing sortdate) $                               -- sort postings by date or date2
+      dbg1 "ps5" $ sortBy (comparing sortdate) $                               -- sort postings by date or date2
+      dbg1 "ps4" $ (if invert_ opts then map negatePostingAmount else id) $    -- with --invert, invert amounts
       dbg1 "ps3" $ map (filterPostingAmount symq) $                            -- remove amount parts which the query's cur: terms would exclude
       dbg1 "ps2" $ (if related_ opts then concatMap relatedPostings else id) $ -- with -r, replace each with its sibling postings
       dbg1 "ps1" $ filter (beforeandduringq `matchesPosting`) $                -- filter postings by the query, with no start date or depth limit
@@ -135,6 +136,9 @@ matchedPostingsBeforeAndDuring opts q j (DateSpan mstart mend) =
       where
         dateq = dbg1 "dateq" $ filterQuery queryIsDateOrDate2 $ dbg1 "q" q  -- XXX confused by multiple date:/date2: ?
 
+negatePostingAmount :: Posting -> Posting
+negatePostingAmount p = p { pamount = negate $ pamount p }
+
 -- | Generate postings report line items from a list of postings or (with
 -- non-Nothing dates attached) summary postings.
 postingsReportItems :: [(Posting,Maybe Day)] -> (Posting,Maybe Day) -> WhichDate -> Int -> MixedAmount -> (Int -> MixedAmount -> MixedAmount -> MixedAmount) -> Int -> [PostingsReportItem]
diff --git a/hledger/Hledger/Cli/Commands/Register.hs b/hledger/Hledger/Cli/Commands/Register.hs
index c700746ea..d544f2a43 100644
--- a/hledger/Hledger/Cli/Commands/Register.hs
+++ b/hledger/Hledger/Cli/Commands/Register.hs
@@ -36,6 +36,7 @@ registermode = hledgerCommandMode
   ,flagNone ["average","A"] (setboolopt "average")
      "show running average of posting amounts instead of total (implies --empty)"
   ,flagNone ["related","r"] (setboolopt "related") "show postings' siblings instead"
+  ,flagNone ["invert"] (setboolopt "invert") "display all amounts with reversed sign"
   ,flagReq  ["width","w"] (\s opts -> Right $ setopt "width" s opts) "N"
      ("set output width (default: " ++
 #ifdef mingw32_HOST_OS