diff --git a/tests/regression/52-apron-mukherjee/02-mukherjee_sigma.c b/tests/regression/52-apron-mukherjee/02-mukherjee_sigma.c
index 333dc64c48..c42f4e42cd 100644
--- a/tests/regression/52-apron-mukherjee/02-mukherjee_sigma.c
+++ b/tests/regression/52-apron-mukherjee/02-mukherjee_sigma.c
@@ -1,4 +1,4 @@
-// SKIP PARAM: --set ana.activated[+] apron --set ana.path_sens[+] threadflag --set ana.activated[+] threadJoins --set ana.relation.privatization mutex-meet-tid
+// SKIP PARAM: --set ana.activated[+] apron --set ana.path_sens[+] threadflag --set ana.activated[+] threadJoins --set ana.relation.privatization mutex-meet-tid --enable ana.apron.strengthening
 
 #include <stdlib.h>
 #include <pthread.h>
diff --git a/tests/regression/52-apron-mukherjee/18-mukherjee_qw2004.c b/tests/regression/52-apron-mukherjee/18-mukherjee_qw2004.c
index 9f3f94beb1..09d2a1177f 100644
--- a/tests/regression/52-apron-mukherjee/18-mukherjee_qw2004.c
+++ b/tests/regression/52-apron-mukherjee/18-mukherjee_qw2004.c
@@ -1,4 +1,4 @@
-// SKIP PARAM: --set ana.activated[+] apron --set ana.path_sens[+] threadflag --set ana.activated[+] threadJoins --enable ana.apron.threshold_widening --set ana.relation.privatization mutex-meet-tid
+// SKIP PARAM: --set ana.activated[+] apron --set ana.path_sens[+] threadflag --set ana.activated[+] threadJoins --enable ana.apron.threshold_widening --set ana.relation.privatization mutex-meet-tid --enable ana.apron.strengthening
 
 #include <pthread.h>
 #include <goblint.h>