diff --git a/Cabal/Distribution/Types/PkgconfigName.hs b/Cabal/Distribution/Types/PkgconfigName.hs
index a0e321fee23..61176687e81 100644
--- a/Cabal/Distribution/Types/PkgconfigName.hs
+++ b/Cabal/Distribution/Types/PkgconfigName.hs
@@ -56,7 +56,13 @@ instance Pretty PkgconfigName where
   pretty = Disp.text . unPkgconfigName
 
 instance Parsec PkgconfigName where
-  parsec = mkPkgconfigName <$> P.munch1 (\c -> isAlphaNum c || c `elem` "+-._")
+    parsec = mkPkgconfigName <$> P.munch1 isNameChar where
+        -- https://gitlab.haskell.org/ghc/ghc/issues/17752
+        isNameChar '-' = True
+        isNameChar '_' = True
+        isNameChar '.' = True
+        isNameChar '+' = True
+        isNameChar c   = isAlphaNum c
 
 instance NFData PkgconfigName where
     rnf (PkgconfigName pkg) = rnf pkg
diff --git a/Cabal/Distribution/Types/PkgconfigVersionRange.hs b/Cabal/Distribution/Types/PkgconfigVersionRange.hs
index f718af92efd..faa704f5fb6 100644
--- a/Cabal/Distribution/Types/PkgconfigVersionRange.hs
+++ b/Cabal/Distribution/Types/PkgconfigVersionRange.hs
@@ -86,7 +86,7 @@ pkgconfigParser = P.spaces >> expr where
     factor = parens expr <|> prim
 
     prim = do
-        op <- P.munch1 (`elem` "<>=^-") P.<?> "operator"
+        op <- P.munch1 isOpChar P.<?> "operator"
         case op of
             "-"  -> anyPkgconfigVersion <$ (P.string "any" *> P.spaces)
 
@@ -98,6 +98,14 @@ pkgconfigParser = P.spaces >> expr where
 
             _ -> P.unexpected $ "Unknown version operator " ++ show op
 
+    -- https://gitlab.haskell.org/ghc/ghc/issues/17752
+    isOpChar '<' = True
+    isOpChar '=' = True
+    isOpChar '>' = True
+    isOpChar '^' = True
+    isOpChar '-' = True
+    isOpChar _   = False
+
     afterOp f = do
         P.spaces
         v <- parsec
diff --git a/Cabal/Distribution/Types/UnitId.hs b/Cabal/Distribution/Types/UnitId.hs
index 4bdb09c9f3b..047a43f27c3 100644
--- a/Cabal/Distribution/Types/UnitId.hs
+++ b/Cabal/Distribution/Types/UnitId.hs
@@ -78,7 +78,13 @@ instance Pretty UnitId where
 -- GHC accepts for @-package-id@.
 --
 instance Parsec UnitId where
-    parsec = mkUnitId <$> P.munch1 (\c -> isAlphaNum c || c `elem` "-_.+")
+    parsec = mkUnitId <$> P.munch1 isUnitChar where
+        -- https://gitlab.haskell.org/ghc/ghc/issues/17752
+        isUnitChar '-' = True
+        isUnitChar '_' = True
+        isUnitChar '.' = True
+        isUnitChar '+' = True
+        isUnitChar c   = isAlphaNum c
 
 -- | If you need backwards compatibility, consider using 'display'
 -- instead, which is supported by all versions of Cabal.
diff --git a/Cabal/Distribution/Types/VersionRange/Internal.hs b/Cabal/Distribution/Types/VersionRange/Internal.hs
index 73605d7e65d..9b84bea9cb3 100644
--- a/Cabal/Distribution/Types/VersionRange/Internal.hs
+++ b/Cabal/Distribution/Types/VersionRange/Internal.hs
@@ -293,7 +293,7 @@ versionRangeParser digitParser = expr
         factor = parens expr <|> prim
 
         prim = do
-            op <- P.munch1 (`elem` "<>=^-") P.<?> "operator"
+            op <- P.munch1 isOpChar P.<?> "operator"
             case op of
                 "-" -> anyVersion <$ P.string "any" <|> P.string "none" *> noVersion'
 
@@ -325,6 +325,14 @@ versionRangeParser digitParser = expr
                         ">"   -> pure $ laterVersion v
                         _ -> fail $ "Unknown version operator " ++ show op
 
+        -- https://gitlab.haskell.org/ghc/ghc/issues/17752
+        isOpChar '<' = True
+        isOpChar '=' = True
+        isOpChar '>' = True
+        isOpChar '^' = True
+        isOpChar '-' = True
+        isOpChar _   = False
+
         -- Note: There are other features:
         -- && and || since 1.8
         -- x.y.* (wildcard) since 1.6