diff --git a/Generate.hs b/Generate.hs
index e230676f..6937b2ae 100755
--- a/Generate.hs
+++ b/Generate.hs
@@ -86,7 +86,7 @@ qualify pw str
     | otherwise = str
     where
         prelude = ["elem","uncurry","snd","fst","not","null","if","then","else"
-                  ,"True","False","Just","Nothing","fromJust","concat","isPrefixOf","isSuffixOf","any"]
+                  ,"True","False","Just","Nothing","fromJust","concat","isPrefixOf","isSuffixOf","any","foldr"]
         fpops = ["</>","<.>","-<.>"]
 
 
diff --git a/System/FilePath/Internal.hs b/System/FilePath/Internal.hs
index 8a1e1391..c3dcb863 100644
--- a/System/FilePath/Internal.hs
+++ b/System/FilePath/Internal.hs
@@ -747,6 +747,7 @@ splitDirectories = map dropTrailingPathSeparator . splitPath
 
 -- | Join path elements back together.
 --
+-- > joinPath a == foldr (</>) "" a
 -- > joinPath ["/","directory/","file.ext"] == "/directory/file.ext"
 -- > Valid x => joinPath (splitPath x) == x
 -- > joinPath [] == ""
diff --git a/System/FilePath/Posix.hs b/System/FilePath/Posix.hs
index b7e61197..219f7d19 100644
--- a/System/FilePath/Posix.hs
+++ b/System/FilePath/Posix.hs
@@ -747,6 +747,7 @@ splitDirectories = map dropTrailingPathSeparator . splitPath
 
 -- | Join path elements back together.
 --
+-- > joinPath a == foldr (</>) "" a
 -- > joinPath ["/","directory/","file.ext"] == "/directory/file.ext"
 -- > Valid x => joinPath (splitPath x) == x
 -- > joinPath [] == ""
diff --git a/System/FilePath/Windows.hs b/System/FilePath/Windows.hs
index 15877020..56aa7197 100644
--- a/System/FilePath/Windows.hs
+++ b/System/FilePath/Windows.hs
@@ -747,6 +747,7 @@ splitDirectories = map dropTrailingPathSeparator . splitPath
 
 -- | Join path elements back together.
 --
+-- > joinPath a == foldr (</>) "" a
 -- > joinPath ["/","directory/","file.ext"] == "/directory/file.ext"
 -- > Valid x => joinPath (splitPath x) == x
 -- > joinPath [] == ""
diff --git a/tests/TestGen.hs b/tests/TestGen.hs
index 6364537d..62eb18f4 100755
--- a/tests/TestGen.hs
+++ b/tests/TestGen.hs
@@ -346,6 +346,8 @@ tests =
     ,("W.splitDirectories \"C:\\\\test\\\\\\\\\\\\file\" == [\"C:\\\\\", \"test\", \"file\"]", property $ W.splitDirectories "C:\\test\\\\\\file" == ["C:\\", "test", "file"])
     ,("P.splitDirectories \"/test///file\" == [\"/\", \"test\", \"file\"]", property $ P.splitDirectories "/test///file" == ["/", "test", "file"])
     ,("W.splitDirectories \"/test///file\" == [\"/\", \"test\", \"file\"]", property $ W.splitDirectories "/test///file" == ["/", "test", "file"])
+    ,("P.joinPath a == foldr (P.</>) \"\" a", property $ \a -> P.joinPath a == foldr (P.</>) "" a)
+    ,("W.joinPath a == foldr (W.</>) \"\" a", property $ \a -> W.joinPath a == foldr (W.</>) "" a)
     ,("P.joinPath [\"/\", \"directory/\", \"file.ext\"] == \"/directory/file.ext\"", property $ P.joinPath ["/", "directory/", "file.ext"] == "/directory/file.ext")
     ,("W.joinPath [\"/\", \"directory/\", \"file.ext\"] == \"/directory/file.ext\"", property $ W.joinPath ["/", "directory/", "file.ext"] == "/directory/file.ext")
     ,("P.joinPath (P.splitPath x) == x", property $ \(QFilePathValidP x) -> P.joinPath (P.splitPath x) == x)