diff --git a/luamml-patches-amsmath.sty b/luamml-patches-amsmath.sty
index f8933c4..733b71b 100644
--- a/luamml-patches-amsmath.sty
+++ b/luamml-patches-amsmath.sty
@@ -399,6 +399,15 @@
   }
 }
 
+% {cases} is defined by the kernel, but we patch the overwritten version by amsmath.
+\cs_set:Npn \env@cases {
+  \let \@ifnextchar \new@ifnextchar
+  \left \lbrace
+    \def \arraystretch {1.2}
+    \array {@{}l@{\quad \luamml_flag_ignore:}l@{}}
+}
+
+
 \cs_set:Npn \bBigg@ #1 #2 {
   {
     \ensuremath {
diff --git a/luamml-patches-kernel.sty b/luamml-patches-kernel.sty
index 457d14d..e03a991 100644
--- a/luamml-patches-kernel.sty
+++ b/luamml-patches-kernel.sty
@@ -34,13 +34,6 @@
   \__luamml_kernel_phantom:Vnn \g__luamml_kernel_phantom_int
 }
 
-\cs_set:Npn \env@cases {
-  \let \@ifnextchar \new@ifnextchar
-  \left \lbrace
-    \def \arraystretch {1.2}
-    \array {@{}l@{\quad \luamml_flag_ignore:}l@{}}
-}
-
 \@ifpackageloaded {unicode-math} {} {
   \cs_new:Npn \__luamml_kernel_define_character:Nnn #1#2#3 {
     \cs_set:cpx { \cs_to_str:N #1 ~ } {