diff --git a/module/lua/lgc.c b/module/lua/lgc.c
index 9363112e4d..55feb24119 100644
--- a/module/lua/lgc.c
+++ b/module/lua/lgc.c
@@ -676,7 +676,7 @@ static void freeobj (lua_State *L, GCObject *o) {
     case LUA_TUSERDATA: luaM_freemem(L, o, sizeudata(gco2u(o))); break;
     case LUA_TSHRSTR:
       G(L)->strt.nuse--;
-      /* go through */
+      /* FALLTHROUGH */
     case LUA_TLNGSTR: {
       luaM_freemem(L, o, sizestring(gco2ts(o)));
       break;
diff --git a/module/lua/llex.c b/module/lua/llex.c
index e98d74320d..8760155d05 100644
--- a/module/lua/llex.c
+++ b/module/lua/llex.c
@@ -474,6 +474,7 @@ static int llex (LexState *ls, SemInfo *seminfo) {
         else if (!lisdigit(ls->current)) return '.';
         /* else go through */
       }
+      /* FALLTHROUGH */
       case '0': case '1': case '2': case '3': case '4':
       case '5': case '6': case '7': case '8': case '9': {
         read_numeral(ls, seminfo);
diff --git a/module/lua/lstrlib.c b/module/lua/lstrlib.c
index cff5e894d4..24a3321bde 100644
--- a/module/lua/lstrlib.c
+++ b/module/lua/lstrlib.c
@@ -501,7 +501,7 @@ static const char *match (MatchState *ms, const char *s, const char *p) {
             }
             case '+':  /* 1 or more repetitions */
               s++;  /* 1 match already done */
-              /* go through */
+              /* FALLTHROUGH */
             case '*':  /* 0 or more repetitions */
               s = max_expand(ms, s, p, ep);
               break;
diff --git a/module/lua/ltable.c b/module/lua/ltable.c
index ea5a43c787..f60418721b 100644
--- a/module/lua/ltable.c
+++ b/module/lua/ltable.c
@@ -492,6 +492,7 @@ const TValue *luaH_get (Table *t, const TValue *key) {
         return luaH_getint(t, k);  /* use specialized version */
       /* else go through */
     }
+    /* FALLTHROUGH */
     default: {
       Node *n = mainposition(t, key);
       do {  /* check whether `key' is somewhere in the chain */