diff --git a/src/common/gamecode/laws.c b/src/common/gamecode/laws.c
index 0044942f0..698a86031 100644
--- a/src/common/gamecode/laws.c
+++ b/src/common/gamecode/laws.c
@@ -1994,7 +1994,11 @@ set_passw(void)
 					} else {
 						i = (int) pow(2, o);
 						if (getparam(u->faction->locale) == P_NOT) {
-							u->faction->options = u->faction->options & ~i;
+							if(i == O_COMPRESS || i == O_BZIP2) {
+								cmistake(u, S->s, 305, MSG_EVENT);
+							} else {
+								u->faction->options = u->faction->options & ~i;
+							}
 						} else {
 							u->faction->options = u->faction->options | i;
 							if(i == O_COMPRESS) u->faction->options &= ~O_BZIP2;
diff --git a/src/res/de/messages.xml b/src/res/de/messages.xml
index 1d841bab1..64b74db1a 100644
--- a/src/res/de/messages.xml
+++ b/src/res/de/messages.xml
@@ -4406,6 +4406,16 @@
 		<text locale="de">"$unit($unit) in $region($region): '$command' - Einheiten einer Partei, die noch immun gegen Angriffe ist, dürfen nicht bewachen."</text>
 		<text locale="en">"$unit($unit) in $region($region): '$command' - units of a faction that can't be attacked may not guard."</text>
 	</message>
+	
+	<message name="error305" section="errors">
+		<type>
+			<arg name="unit" type="unit"></arg>
+			<arg name="region" type="region"></arg>
+			<arg name="command" type="string"></arg>
+		</type>
+		<text locale="de">"$unit($unit) in $region($region): '$command' - Die Optionen ZIP und BZIP2 können nur um, nicht ausgeschaltet werden."</text>
+		<text locale="en">"$unit($unit) in $region($region): '$command' - options ZIP and BZIP2 can only be switched, not turned off."</text>
+	</message>
 
 	<message name="drown_on_ship">
 		<type>