diff -rup fallthrough/jsonc/json_object.c jsonc/jsonc/json_object.c
--- fallthrough/jsonc/json_object.c	2019-04-24 19:04:45.902291502 +0300
+++ jsonc/jsonc/json_object.c	2019-04-25 10:57:37.518731253 +0300
@@ -697,7 +697,9 @@ int64_t json_object_get_int64(const stru
 	case json_type_string:
 		if (json_parse_int64(get_string_component(jso), &cint) == 0)
 			return cint;
-		/* FALLTHRU */
+#if defined(__GNUC__) && __GNUC__ >= 7
+		__attribute__((fallthrough));
+#endif
 	default:
 		return 0;
 	}
diff -rup fallthrough/jsonc/json_tokener.c jsonc/jsonc/json_tokener.c
--- fallthrough/jsonc/json_tokener.c	2019-04-24 19:04:45.906291502 +0300
+++ jsonc/jsonc/json_tokener.c	2019-04-25 10:56:31.493729590 +0300
@@ -346,7 +346,9 @@ struct json_object* json_tokener_parse_e
             tok->err = json_tokener_error_parse_unexpected;
             goto out;
         }
-	/* FALLTHRU */
+#if defined(__GNUC__) && __GNUC__ >= 7
+	__attribute__((fallthrough));
+#endif
       case '"':
 	state = json_tokener_state_string;
 	printbuf_reset(tok->pb);
diff -rup fallthrough/jsonc/linkhash.c jsonc/jsonc/linkhash.c
--- fallthrough/jsonc/linkhash.c	2019-04-24 19:04:45.911291503 +0300
+++ jsonc/jsonc/linkhash.c	2019-04-25 12:02:40.764829548 +0300
@@ -31,6 +31,12 @@
 #include "random_seed.h"
 #include "linkhash.h"
 
+#if defined(__GNUC__) && __GNUC__ >= 7
+#define IMPLICIT_FALLTHROUGH __attribute__((fallthrough))
+#else
+#define IMPLICIT_FALLTHROUGH ((void)0)
+#endif
+
 /* hash functions */
 static unsigned long lh_char_hash(const void *k);
 static unsigned long lh_perllike_str_hash(const void *k);
@@ -366,22 +372,27 @@ static uint32_t hashlittle( const void *
              a+=k[0]+(((uint32_t)k[1])<<16);
              break;
     case 11: c+=((uint32_t)k8[10])<<16;     /* fall through */
+             IMPLICIT_FALLTHROUGH;
     case 10: c+=k[4];
              b+=k[2]+(((uint32_t)k[3])<<16);
              a+=k[0]+(((uint32_t)k[1])<<16);
              break;
     case 9 : c+=k8[8];                      /* fall through */
+             IMPLICIT_FALLTHROUGH;
     case 8 : b+=k[2]+(((uint32_t)k[3])<<16);
              a+=k[0]+(((uint32_t)k[1])<<16);
              break;
     case 7 : b+=((uint32_t)k8[6])<<16;      /* fall through */
+             IMPLICIT_FALLTHROUGH;
     case 6 : b+=k[2];
              a+=k[0]+(((uint32_t)k[1])<<16);
              break;
     case 5 : b+=k8[4];                      /* fall through */
+             IMPLICIT_FALLTHROUGH;
     case 4 : a+=k[0]+(((uint32_t)k[1])<<16);
              break;
     case 3 : a+=((uint32_t)k8[2])<<16;      /* fall through */
+             IMPLICIT_FALLTHROUGH;
     case 2 : a+=k[0];
              break;
     case 1 : a+=k8[0];
@@ -416,16 +427,27 @@ static uint32_t hashlittle( const void *
     switch(length)                   /* all the case statements fall through */
     {
     case 12: c+=((uint32_t)k[11])<<24; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 11: c+=((uint32_t)k[10])<<16; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 10: c+=((uint32_t)k[9])<<8; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 9 : c+=k[8]; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 8 : b+=((uint32_t)k[7])<<24; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 7 : b+=((uint32_t)k[6])<<16; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 6 : b+=((uint32_t)k[5])<<8; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 5 : b+=k[4]; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 4 : a+=((uint32_t)k[3])<<24; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 3 : a+=((uint32_t)k[2])<<16; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 2 : a+=((uint32_t)k[1])<<8; /* FALLTHRU */
+             IMPLICIT_FALLTHROUGH;
     case 1 : a+=k[0];
              break;
     case 0 : return c;