diff --git a/bin/argbash b/bin/argbash
index 7a71d4e..1088e62 100755
--- a/bin/argbash
+++ b/bin/argbash
@@ -495,7 +495,7 @@ then
 	# match against suspicious, then inverse match against correct stuff:
 	# #<optional whitespace>\(allowed\|another allowed\|...\)<optional whitespace><opening bracket <or> end of line>
 	# Then, extract all matches (assumed to be alnum chars + '_') from grep and put them in the error msg.
-	grep_output="$(printf "%s" "$output" | grep '^#\s*\(ARG_\|ARGBASH\)' | grep -v '^#\s*\(ARGBASH_SET_INDENT\|ARG_OPTIONAL_SINGLE\|ARG_VERSION\|ARG_VERSION_AUTO\|ARG_HELP\|ARG_OPTIONAL_INCREMENTAL\|ARG_OPTIONAL_REPEATED\|ARG_VERBOSE\|ARG_OPTIONAL_BOOLEAN\|ARG_OPTIONAL_ACTION\|ARG_POSITIONAL_SINGLE\|ARG_POSITIONAL_INF\|ARG_POSITIONAL_MULTI\|ARG_POSITIONAL_DOUBLEDASH\|ARG_OPTION_STACKING\|ARG_RESTRICT_VALUES\|ARG_DEFAULTS_POS\|ARG_LEFTOVERS\|ARGBASH_WRAP\|INCLUDE_PARSING_CODE\|DEFINE_SCRIPT_DIR\|DEFINE_SCRIPT_DIR_GNU\|ARGBASH_SET_DELIM\|ARGBASH_GO\|ARGBASH_PREPARE\|ARG_TYPE_GROUP\|ARG_TYPE_GROUP_SET\|ARG_USE_ENV\|ARG_USE_PROG\)\s*\((\|$\)' | sed -e 's/#\s*\([[:alnum:]_]*\).*/\1 /' | tr -d '\n\r')"
+	grep_output="$(printf "%s" "$output" | grep '^#\s*\(ARG_\|ARGBASH\)' | grep -v '^#\s*\(ARGBASH_SET_INDENT\|ARG_OPTIONAL_SINGLE\|ARG_VERSION\|ARG_VERSION_AUTO\|ARG_HELP\|ARG_OPTIONAL_INCREMENTAL\|ARG_OPTIONAL_REPEATED\|ARG_VERBOSE\|ARG_OPTIONAL_BOOLEAN\|ARG_OPTIONAL_SWITCH_ON\|ARG_OPTIONAL_SWITCH_OFF\|ARG_OPTIONAL_ACTION\|ARG_POSITIONAL_SINGLE\|ARG_POSITIONAL_INF\|ARG_POSITIONAL_MULTI\|ARG_POSITIONAL_DOUBLEDASH\|ARG_OPTION_STACKING\|ARG_RESTRICT_VALUES\|ARG_DEFAULTS_POS\|ARG_LEFTOVERS\|ARGBASH_WRAP\|INCLUDE_PARSING_CODE\|DEFINE_SCRIPT_DIR\|DEFINE_SCRIPT_DIR_GNU\|ARGBASH_SET_DELIM\|ARGBASH_GO\|ARGBASH_PREPARE\|ARG_TYPE_GROUP\|ARG_TYPE_GROUP_SET\|ARG_USE_ENV\|ARG_USE_PROG\)\s*\((\|$\)' | sed -e 's/#\s*\([[:alnum:]_]*\).*/\1 /' | tr -d '\n\r')"
 	test -n "$grep_output" && die "Your script contains possible misspelled Argbash macros: $grep_output" 1
 fi
 if test "$outfname" != '-'
diff --git a/src/collectors.m4 b/src/collectors.m4
index 798885f..74625ba 100644
--- a/src/collectors.m4
+++ b/src/collectors.m4
@@ -1,6 +1,30 @@
 m4_define([_COLLECTOR_FEEDBACK], [m4_fatal($@)])
 
 
+dnl
+dnl $1: The key
+m4_define([_FORMAT_MISSING_PREFIX], [m4_do(
+	[[The prefix for option '$1' has not been found]],
+)])
+
+dnl
+dnl $1: The argname(i.e. storage key)
+dnl $2: The prefix
+m4_define([STORE_NEGATION_PREFIX], [m4_do(
+	[m4_define([_NEG_PREFIX_FOR_$1], [[$2]])],
+)])
+
+
+dnl
+dnl $1: The argname(i.e. storage key)
+dnl $2: Error-handling callback that is given the error message as the first argument.
+m4_define([GET_NEGATION_PREFIX], [m4_do(
+	[m4_ifndef([_NEG_PREFIX_FOR_$1],
+		[m4_default([$2], [m4_fatal])([_FORMAT_MISSING_PREFIX([$1])])],
+		[m4_quote(m4_indir([_NEG_PREFIX_FOR_$1]))])],
+)])
+
+
 dnl
 dnl $1: The argument name
 dnl $2: The help message
@@ -324,10 +348,48 @@ dnl $3: help
 dnl $4: default (=off)
 argbash_api([ARG_OPTIONAL_BOOLEAN], _CHECK_PASSED_ARGS_COUNT(1, 4)[m4_do(
 	[[$0($@)]],
-	[m4_ifnblank([$4], [m4_case([$4], [on], , [off], ,
-		[_COLLECTOR_FEEDBACK([Problem with argument '$1': Only 'on' or 'off' are allowed as boolean defaults, you have specified '$4'.])])])],
-	[_ADD_OPTIONAL_ARGUMENT_IF_POSSIBLE([$1], [$2], [$3],
-		m4_default_quoted([$4], [off]), [bool])],
+	[m4_ifnblank([$4],
+		[m4_case([$4],
+			[off], [_ARG_OPTIONAL_SWITCH_ON([$1], [$2], [$3])],
+			[on], [_ARG_OPTIONAL_SWITCH_OFF([$1], [$2], [$3])],
+			[_COLLECTOR_FEEDBACK([Problem with argument '$1': Only 'on' or 'off' are allowed as boolean defaults, you have specified '$4'.])])],
+		[_ADD_OPTIONAL_ARGUMENT_IF_POSSIBLE([$1], [$2], [$3],
+			m4_default_quoted([$4], [off]), [bool])],
+	)],
+)])
+
+
+dnl $1: long name, var suffix (translit of [-] -> _)
+dnl $2: short name (opt)
+dnl $3: help
+argbash_api([ARG_OPTIONAL_SWITCH_ON], _CHECK_PASSED_ARGS_COUNT(1, 3)[m4_do(
+	[[$0($@)]],
+	[_ARG_OPTIONAL_SWITCH_ON($@)],
+)])
+
+
+m4_define([_ARG_OPTIONAL_SWITCH_ON], _CHECK_PASSED_ARGS_COUNT(1, 3)[m4_do(
+	[_ADD_OPTIONAL_ARGUMENT_IF_POSSIBLE([$1], [$2], [$3], [off], [bool])],
+)])
+
+
+m4_define([_DEFAULT_NEGATION_PREFIX], [[no-]])
+
+m4_define([ARG_SET_DEFAULT_NEGATION_PREFIX], [m4_define([_DEFAULT_NEGATION_PREFIX], [[$1]])])
+
+dnl $1: long name, var suffix (translit of [-] -> _)
+dnl $2: short name (opt)
+dnl $3: help
+dnl $4: the negation prefix (=no-, resulting in i.e. --no-video)
+argbash_api([ARG_OPTIONAL_SWITCH_OFF], _CHECK_PASSED_ARGS_COUNT(1, 4)[m4_do(
+	[[$0($@)]],
+	[_ARG_OPTIONAL_SWITCH_OFF($@)],
+)])
+
+
+m4_define([_ARG_OPTIONAL_SWITCH_OFF], _CHECK_PASSED_ARGS_COUNT(1, 4)[m4_do(
+	[STORE_NEGATION_PREFIX([$1], m4_default_quoted([$4], _DEFAULT_NEGATION_PREFIX))],
+	[_ADD_OPTIONAL_ARGUMENT_IF_POSSIBLE([$1], [$2], [$3], [on], [bool])],
 )])
 
 
diff --git a/src/function_generators.m4 b/src/function_generators.m4
index 6b2ced1..0727147 100644
--- a/src/function_generators.m4
+++ b/src/function_generators.m4
@@ -168,7 +168,7 @@ m4_define([_MAKE_ARGV_PARSING_FUNCTION], [MAKE_FUNCTION(
 	[parse_commandline], [m4_do(
 		[_JOIN_INDENTED(1,
 			_IF_HAVE_POSITIONAL_ARGS([[_positionals_count=0],]),
-			[while test $[]# -gt 0],
+			[[while test $][# -gt 0]],
 			[do],
 		)],
 		[_IF_HAVE_OPTIONAL_ARGS(
@@ -193,8 +193,8 @@ m4_define([_MAKE_ARGV_PARSING_FUNCTION_POSIX], [MAKE_FUNCTION(
 	[[The parsing of the command-line]],
 	[parse_commandline], [m4_do(
 		[_JOIN_INDENTED(1,
-			[while getopts '_GET_GETOPTS_STRING()' _key],
-			[do],
+			[[while getopts ']_GET_GETOPTS_STRING()[' _key]],
+			[[do]],
 		)],
 		[_EVAL_OPTIONALS_GETOPTS],
 		[_INDENT_()done[]_ENDL_()],
diff --git a/src/stuff.m4 b/src/stuff.m4
index 5b1231e..8a5e700 100644
--- a/src/stuff.m4
+++ b/src/stuff.m4
@@ -422,7 +422,7 @@ dnl $3: Name of the value-to-variable macro
 dnl $4: The name of the argument-holding variable
 dnl $5: Where to get the last value (optional)
 m4_define([_VAL_OPT_ADD_SPACE_WITHOUT_GETOPT_OR_SHORT_OPT], [_JOIN_INDENTED(_INDENT_LEVEL_IN_ARGV_CASE_BODY,
-	[test $[]# -lt 2 && die "Missing value for the optional argument '$_key'." 1],
+	[[test $][# -lt 2 && die "Missing value for the optional argument '$_key'." 1]],
 	[$3([$1], ["@S|@2"], [$4])],
 	[_APPEND_WRAPPED_ARGUMENT_TO_ARRAY_SPACE([$4], [m4_default_quoted([$5], [@S|@2])])],
 	[shift],
diff --git a/start_tmux.sh b/start_tmux.sh
index 33ced19..7793d42 100644
--- a/start_tmux.sh
+++ b/start_tmux.sh
@@ -4,6 +4,6 @@ tmux send-keys 'vim stuff.m4' C-m
 tmux new-window -c resources
 tmux send-keys -l 'make unittests'
 tmux new-window -c tests/unittests
-tmux send-keys -l 'vim '
+tmux send-keys -l 'vim -p test-support.m4 '
 tmux select-window -t argbash:0
 tmux -2 attach-session -t argbash
diff --git a/tests/regressiontests/test-onlyopt.m4 b/tests/regressiontests/test-onlyopt.m4
index 19eefa3..0c2c0da 100644
--- a/tests/regressiontests/test-onlyopt.m4
+++ b/tests/regressiontests/test-onlyopt.m4
@@ -2,7 +2,7 @@
 
 m4_define([if_not_posix], [m4_if(m4_quote(_OUTPUT_TYPE), [posix-script], [$2], [$1])])
 
-dnl m4_define([test], [m4_fatal([BOOM!!!])])
+dnl m4_define([test], [huuuuuuuuuu])
 m4_define([incrx], [m4_fatal([BOOM!!!])])
 # ARG_OPTIONAL_SINGLE([opt-arg], o, [@opt-arg@], x)
 # ARG_VERSION([echo "$0 FOO"])
diff --git a/tests/unittests/check-arguments.m4 b/tests/unittests/check-arguments.m4
index 96a3e17..60867df 100644
--- a/tests/unittests/check-arguments.m4
+++ b/tests/unittests/check-arguments.m4
@@ -44,6 +44,9 @@ assert_equals([not single], _CATH_IS_SINGLE_VALUED(m4_list_nth([_ARGS_CATH], 4),
 
 _DISCARD_VALUES_FOR_ALL_ARGUMENTS()
 
+assert_equals(m4_list_len([_ARGS_LONG]), 0)
+
+
 ARG_OPTIONAL_SINGLE([foo], [f], [Help,BOMB], [Default])
 ARG_POSITIONAL_SINGLE([defaultless], [xhelp])
 ARG_POSITIONAL_MULTI([multi-BOMB], [help-BOMB], 3, [one], [two])
@@ -103,3 +106,23 @@ ARG_OPTIONAL_SINGLE([bar], [f])
 assert_equals(m4_list_len([_ERRORS_]), 1)
 m4_bmatch(m4_list_nth([_ERRORS_], 1), ['f'.*already used], [], [m4_fatal([Expected error reflecting duplicate short option, got] 'm4_list_nth([_ERRORS_], 1)' instead.)])
 m4_popdef([_COLLECTOR_FEEDBACK])
+
+_DISCARD_VALUES_FOR_ALL_ARGUMENTS()
+
+ARG_OPTIONAL_SWITCH_ON([foo], [f])
+assert_equals_list_element([_ARGS_LONG], 1, [foo])
+assert_equals_list_element([_ARGS_DEFAULT], 1, [off])
+
+ARG_OPTIONAL_SWITCH_OFF([bar], [b], , [BOMB])
+assert_equals_list_element([_ARGS_LONG], 2, [bar])
+assert_equals_list_element([_ARGS_DEFAULT], 2, [on])
+assert_equals(GET_NEGATION_PREFIX([bar]), [BOMB])
+
+ARG_OPTIONAL_SWITCH_OFF([BOMB])
+assert_equals_list_element([_ARGS_LONG], 3, [BOMB])
+assert_equals_list_element([_ARGS_DEFAULT], 2, [on])
+assert_equals(GET_NEGATION_PREFIX([BOMB]), [no-])
+
+ARG_SET_DEFAULT_NEGATION_PREFIX([BOMB])
+ARG_OPTIONAL_SWITCH_OFF([xx])
+assert_equals(GET_NEGATION_PREFIX([xx]), [BOMB])
diff --git a/tests/unittests/check-collectors.m4 b/tests/unittests/check-collectors.m4
new file mode 100644
index 0000000..6be3fb0
--- /dev/null
+++ b/tests/unittests/check-collectors.m4
@@ -0,0 +1,12 @@
+m4_include([collectors.m4])
+
+m4_include([test-support.m4])
+
+
+m4_define([SAVE], [m4_define([SAVED], [$1])])
+
+GET_NEGATION_PREFIX([BOMB], [SAVE])
+assert_equals(SAVED, _FORMAT_MISSING_PREFIX([BOMB]))
+
+STORE_NEGATION_PREFIX([lol], [BOMB])
+assert_equals(GET_NEGATION_PREFIX([lol]), [BOMB])