diff --git a/share/completions/patch.fish b/share/completions/patch.fish
index be71824ad..6f329a155 100644
--- a/share/completions/patch.fish
+++ b/share/completions/patch.fish
@@ -1,41 +1,46 @@
 #
-# Completions for patch
+# Completions for GNU patch
+# TODO: POSIX patch
 #
 
-complete -c patch -s b -l backup -d "Make backup files, when patching a file, rename or copy the original instead of removing it"
-complete -c patch -l backup-if-mismatch -d "Back up a file if the patch does not match the file exactly"
-complete -c patch -l no-backup-if-mismatch -d "Do not back up a file if the patch does not match the file exactly"
-complete -c patch -s B -l prefix -r -f -d "Prefix pref to a file name when generating its simple backup file name"
-complete -c patch -l binary -d "Read and write all files in binary mode"
-complete -c patch -s c -l context -d "Interpret the patch file as a ordinary context diff"
-complete -c patch -s d -l directory -xa '(__fish_complete_directories (commandline -ct))' -d "Change to the directory dir immediately"
-complete -c patch -s D -l ifdef -r -f -d "Use the #ifdef…#endif construct to mark changes"
-complete -c patch -l dry-run -d "Print the results of applying the patches without actually changing any files"
-complete -c patch -s e -l ed -d "Interpret the patch file as an ed script"
-complete -c patch -s E -l remove-empty-files -d "Remove output files that are empty after the patches have been applied"
-complete -c patch -s f -l force -d "Assume that the user knows exactly what he/she is doing, and do not ask questions"
-complete -c patch -s F -l fuzz -r -f -d "Set the maximum fuzz factor"
-complete -c patch -s g -l get -r -f -d "This option controls patch's actions when a file is under RCS or SCCS control, and does not exist or is read-only and matches the default version, or when a file is under ClearCase control and does not exist"
-complete -c patch -l help -d "Display help and exit"
-complete -c patch -s i -l input -r -d "Read the patch from patchfile"
-complete -c patch -s l -l ignore-whitespace -d "Match patterns loosely, in case tabs or spaces have been munged in your files"
-complete -c patch -s n -l normal -d "Interpret the patch file as a normal diff"
-complete -c patch -s N -l forward -d "Ignore patches that seem to be reversed or already applied"
-complete -c patch -s o -l output -r -d "Send output to outfile instead of patching files in place"
-complete -c patch -s p -l strip -r -f -d "Strip the smallest prefix containing num leading slashes from each file name found in the patch file"
-complete -c patch -l posix -d "Conform more strictly to the POSIX standard"
-complete -c patch -l quoting-style -r -f -d "Use style word to quote output names" -a "literal shell shell-always c escape"
-complete -c patch -s r -l reject-file -r -d "Put rejects into rejectfile instead of the default .rej file"
-complete -c patch -s R -l reverse -d "Assume that this patch was created with the old and new files swapped"
-complete -c patch -s s -l silent -l quiet -d "Work silently, unless an error occurs"
-complete -c patch -s t -l batch -d "Suppress questions like -f, but make some different assumptions"
-complete -c patch -s T -l set-time -d "Set the modification and access times of patched files from time stamps given in context diff headers, local time"
-complete -c patch -s u -l unified -d "Interpret the patch file as a unified context diff"
-complete -c patch -s v -l version -d "Display version and exit"
-complete -c patch -s V -l version-control -r -f -d "Use method to determine backup file names"
-complete -c patch -l verbose -d "Output extra information about the work being done"
-complete -c patch -s x -l debug -r -f -d "Set internal debugging flags of interest only to patch patchers"
-complete -c patch -s Y -l basename-prefix -r -f -d "Prefix pref to the basename of a file name when generating its simple backup file name"
-complete -c patch -s z -l suffix -r -f -d "Use suffix as the simple backup suffix"
-complete -c patch -s Z -l set-utc -d "Set the modification and access times of patched files from time stamps given in context diff headers, UTC, GMT"
+complete -c patch -s b -l backup -d "Back up the original contents of each file"
+complete -c patch -l backup-if-mismatch -d "Back up files if patch doesn't match exactly"
+complete -c patch -l no-backup-if-mismatch -d "Don't back up for mismatching patches"
+complete -c patch -s B -l prefix -x -d "Prepend PREFIX to backup filenames"
+complete -c patch -s c -l context -d "Interpret patch as context diff"
+complete -c patch -s d -l directory -xa '(__fish_complete_directories (commandline -ct))' -d "Change directory to DIR first"
+complete -c patch -s D -l ifdef -x -d "Make merged if-then-else output using NAME"
+complete -c patch -l dry-run -d "Don't change files; just print what would happen"
+complete -c patch -s e -l ed -d "Interpret patch as an 'ed' script"
+complete -c patch -s E -l remove-empty-files -d "Remove output files empty after patching"
+complete -c patch -s f -l force -d "Like -t, but ignore bad-Prereq patches, assume unreversed"
+complete -c patch -s F -l fuzz -x -d "Number of LINES for inexact 'fuzzy' matching" -a "(seq 0 9){\tfuzz lines}"
+complete -c patch -s g -l get -x -d "Get files from RCS etc. if positive; ask if negative" -a '(seq -1 1){\t\n}'
+complete -c patch -l help -f -d "Display help"
+complete -c patch -s i -l input -x -d "Read patch from FILE instead of stdin" -a "( __fish_complete_suffix .patch
+																					__fish_complete_suffix .diff )"
+complete -c patch -s l -l ignore-whitespace -d "Ignore whitespace changes between patch & input"
+complete -c patch -s n -l normal -d "Interpret patch as normal diff"
+complete -c patch -s N -l forward -d "Ignore patches that seem reversed or already applied"
+complete -c patch -s o -l output -r -d "Output patched files to FILE"
+complete -c patch -s p -l strip -x -d "Strip NUM path components from filenames" -a "(seq 0 9){\t\n}"
+complete -c patch -l posix -d "Conform to the POSIX standard"
+complete -c patch -l quoting-style -x -d "Output file names using quoting style" -a "literal shell shell-always c escape"
+complete -c patch -s r -l reject-file -r -d "Output rejects to FILE"
+complete -c patch -s R -l reverse -d "Assume patches were created with old/new files swapped"
+complete -c patch -s s -l silent -l quiet -d "Work silently unless an error occurs"
+complete -c patch -s t -l batch -d "Ask no questions; skip bad-Prereq patches; assume reversed"
+complete -c patch -s T -l set-time -d "Set times of patched files assuming diff uses local time"
+complete -c patch -s u -l unified -d "Interpret patch file as a unified diff"
+complete -c patch -s v -l version -d "Display version"
+complete -c patch -s V -l version-control -x -d "Use method to determine backup file names" -a "simple numbered existing"
+complete -c patch -l verbose -d "Output extra information about work being done"
+complete -c patch -s x -l debug -x -d "Set internal debugging flags"
+complete -c patch -s Y -l basename-prefix -x -d "Prepend PREFIX to backup file basenames"
+complete -c patch -s z -l suffix -x -d "Append SUFFIX to backup file name"
+complete -c patch -s Z -l set-utc -d "Set times of patched files assuming diff uses UTC"
+
+# No effect on POSIX systems that don't use O_BINARY/O_TEXT
+uname -s | string match -q CYGWIN\*
+and complete -c patch -l binary -d "Read & write data in binary mode"