diff --git a/.github/packaging/postinstall_macos b/.github/packaging/postinstall_macos
index 31f45d2..c8a7650 100755
--- a/.github/packaging/postinstall_macos
+++ b/.github/packaging/postinstall_macos
@@ -25,6 +25,7 @@ autoload -Uz compinit
 compinit
 # <<< specs completion <<<
 EOF
+    echo "Enabling auto-complete on this machine. Restarting the terminal many be required."
 fi
 
 exit 0
diff --git a/.github/packaging/postuninstall_macos b/.github/packaging/postuninstall_macos
new file mode 100755
index 0000000..99a6a40
--- /dev/null
+++ b/.github/packaging/postuninstall_macos
@@ -0,0 +1,33 @@
+#!/bin/bash
+# Disable the zsh completion for specs that was enabled by postinstall_macos.
+#
+# This script is the counterpart of postinstall_macos. It is used by the local
+# "make uninstall" target to undo the change postinstall_macos made to
+# /etc/zshrc, so the behaviour stays symmetric with installation.
+#
+# It is idempotent: the sentinel-wrapped block is only removed when the markers
+# are present, so running it any number of times never fails or touches an
+# /etc/zshrc that we never modified.
+set -e
+
+ZSHRC="/etc/zshrc"
+MARKER="# >>> specs completion >>>"
+END_MARKER="# <<< specs completion <<<"
+
+if grep -qF "$MARKER" "$ZSHRC" 2>/dev/null; then
+    tmp="$(mktemp)"
+    # Drop the sentinel-wrapped block as well as any blank line(s) that
+    # immediately precede it (postinstall_macos inserts one before the block).
+    awk -v start="$MARKER" -v end="$END_MARKER" '
+        $0 == start { blanks = ""; inblock = 1; next }
+        inblock     { if ($0 == end) inblock = 0; next }
+        /^[[:space:]]*$/ { blanks = blanks $0 "\n"; next }
+        { printf "%s", blanks; blanks = ""; print }
+        END { printf "%s", blanks }
+    ' "$ZSHRC" > "$tmp"
+    cat "$tmp" > "$ZSHRC"
+    /bin/rm -f "$tmp"
+    echo "Disabling auto-complete on this machine"
+fi
+
+exit 0
diff --git a/specs/src/setup.py b/specs/src/setup.py
index 7bab222..ba61c93 100644
--- a/specs/src/setup.py
+++ b/specs/src/setup.py
@@ -263,6 +263,22 @@ def python_search(arg):
 
 install_win: $(EXE_DIR)/specs.exe
 	echo "Please copy the file specs.exe in the EXE dir to a location on the PATH"
+
+uninstall_mac:
+	/bin/rm -f /usr/local/bin/specs
+	/bin/rm -f /usr/local/bin/specs-autocomplete
+	/bin/rm -f /usr/local/share/man/man1/specs.1.gz
+	/bin/rm -f /usr/local/share/zsh/site-functions/_specs
+	/bin/bash ../../.github/packaging/postuninstall_macos
+
+uninstall_linux:
+	/bin/rm -f /usr/local/bin/specs
+	/bin/rm -f /usr/local/bin/specs-autocomplete
+	/bin/rm -f /usr/local/share/man/man1/specs.1.gz
+	/bin/rm -f /etc/bash_completion.d/specs
+
+uninstall_win:
+	echo "Installation on Windows only copies specs.exe to the PATH; nothing to uninstall. Please manually remove specs.exe if desired."
 """
 
 clear_clean_posix = \
@@ -816,10 +832,10 @@ def python_search(arg):
 	makefile.write("{}\n".format(clear_clean_part))
 
 	if sys.platform=="darwin":
-		makefile.write("{}\n\ninstall: install_mac\n".format(manpart))
+		makefile.write("{}\n\ninstall: install_mac\n\nuninstall: uninstall_mac\n".format(manpart))
 	elif platform=="NT":
-		makefile.write("install: install_win\n")
+		makefile.write("install: install_win\n\nuninstall: uninstall_win\n")
 	else:
-		makefile.write("{}\n\ninstall: install_linux\n".format(manpart))
+		makefile.write("{}\n\ninstall: install_linux\n\nuninstall: uninstall_linux\n".format(manpart))
 
 sys.stderr.write("Makefile created.\n")