diff --git a/share/completions/env.fish b/share/completions/env.fish
index b845c94da..838296501 100644
--- a/share/completions/env.fish
+++ b/share/completions/env.fish
@@ -16,7 +16,7 @@ end
 # Returns 0 if we're after `env` and all previous tokens have not yet contained an equal sign
 # Prevents `env` completions from completing payload completions.
 function __fish_env_not_yet_vars
-    not string match -qe = (commandline -c)
+    not string match -qe -- = (commandline -c)
 end
 
 # Generate a list of possible variable names to redefine, excluding any already redefined.
@@ -43,7 +43,7 @@ end
 
 # Generate a list of possible completions for the current variable name from history
 function __fish_env_values_from_history
-    string match -rq "(?<name>.+)=(?<value>.*)" (commandline -ct); or return 1
+    string match -rq -- "(?<name>.+)=(?<value>.*)" (commandline -ct); or return 1
 
     # Caveat lector: very crude multi-word tokenization handling below!
     set -l rname (string escape --style=regex -- $name)
diff --git a/share/completions/scp.fish b/share/completions/scp.fish
index 4d92e0c22..87408a52d 100644
--- a/share/completions/scp.fish
+++ b/share/completions/scp.fish
@@ -37,7 +37,7 @@ end
 #
 
 # Inherit user/host completions from ssh
-complete -c scp -d Remote -n "__fish_no_scp_remote_specified; and not string match -e : (commandline -ct)" -a "(complete -C'ssh ' | string replace -r '\t.*' ':')"
+complete -c scp -d Remote -n "__fish_no_scp_remote_specified; and not string match -e -- : (commandline -ct)" -a "(complete -C'ssh ' | string replace -r '\t.*' ':')"
 
 # Local path
 complete -c scp -d "Local Path" -n "not string match @ -- (commandline -ct)"
diff --git a/share/completions/zabbix_agentd.fish b/share/completions/zabbix_agentd.fish
index e6c0c6280..b00efc785 100644
--- a/share/completions/zabbix_agentd.fish
+++ b/share/completions/zabbix_agentd.fish
@@ -5,7 +5,7 @@ set -l runtime userparameter_reload \
     log_level_decrease=
 
 function __fish_string_in_command -a ch
-    string match -rq $ch (commandline)
+    string match -rq -- $ch (commandline)
 end
 
 function __fish_prepend -a prefix
diff --git a/share/completions/zabbix_proxy.fish b/share/completions/zabbix_proxy.fish
index d6baec4fb..abb6e15cb 100644
--- a/share/completions/zabbix_proxy.fish
+++ b/share/completions/zabbix_proxy.fish
@@ -9,7 +9,7 @@ set -l runtime config_cache_reload \
     log_level_decrease=
 
 function __fish_string_in_command -a ch
-    string match -rq $ch (commandline)
+    string match -rq -- $ch (commandline)
 end
 
 function __fish_prepend -a prefix
diff --git a/share/completions/zabbix_server.fish b/share/completions/zabbix_server.fish
index 028a99efe..4e52fd606 100644
--- a/share/completions/zabbix_server.fish
+++ b/share/completions/zabbix_server.fish
@@ -21,7 +21,7 @@ set -l runtime config_cache_reload \
 set -l scope rwlock mutex processing
 
 function __fish_string_in_command -a ch
-    string match -rq $ch (commandline)
+    string match -rq -- $ch (commandline)
 end
 
 function __fish_prepend -a prefix
diff --git a/share/functions/__fish_npm_helper.fish b/share/functions/__fish_npm_helper.fish
index ea84dd325..1e154611a 100644
--- a/share/functions/__fish_npm_helper.fish
+++ b/share/functions/__fish_npm_helper.fish
@@ -30,7 +30,7 @@ function __npm_filtered_list_packages
     end
 
     # Do not provide any completions if nothing has been entered yet to avoid long hang.
-    if string match -rq . (commandline -ct)
+    if string match -rq -- . (commandline -ct)
         # Filter the results here rather than in the C++ code due to #5267
         # `all-the-package-names` reads a billion line JSON file using node (slow) then prints
         # it all (slow) using node (slow). Directly parse the `names.json` file that ships with it instead.