diff --git a/share/functions/__fish_make_completion_signals.fish b/share/functions/__fish_make_completion_signals.fish
index 8c6c930c0..9a86a3165 100644
--- a/share/functions/__fish_make_completion_signals.fish
+++ b/share/functions/__fish_make_completion_signals.fish
@@ -4,6 +4,18 @@ function __fish_make_completion_signals --description 'Make list of kill signals
 
     set -g __kill_signals
 
+    # Cygwin's kill is special, and the documentation lies.
+    # Just hardcode the signals.
+    if uname | string match -q 'CYGWIN*'
+        set -a __kill_signals "1 HUP" "2 INT" "3 QUIT" "4 ILL" "5 TRAP" "6 ABRT" \
+        "6 IOT" "7 BUS" "8 FPE" "9 KILL" "10 USR1" "11 SEGV" \
+        "12 USR2" "13 PIPE" "14 ALRM" "15 TERM" "16 STKFLT" "17 CHLD" \
+        "17 CLD" "18 CONT" "19 STOP" "20 TSTP" "21 TTIN" "22 TTOU" \
+        "23 URG" "24 XCPU" "25 XFSZ" "26 VTALRM" "27 PROF" "28 WINC" \
+        "29 IO" "29 POLL" "30 PWR" "31 SYS" "34 RTMIN" "64 RTMA"
+        return
+    end
+
     # Some systems use the GNU coreutils kill command where `kill -L` produces an extended table
     # format that looks like this:
     #