diff --git a/src/core/snmp/msg_in.c b/src/core/snmp/msg_in.c
index 275c84ce..90f1b1ba 100644
--- a/src/core/snmp/msg_in.c
+++ b/src/core/snmp/msg_in.c
@@ -51,7 +51,7 @@
 /** SNMP v1 == 0 */
 const s32_t snmp_version = 0;
 /** default SNMP community string */
-const char snmp_publiccommunity[7] = "public";
+const char snmp_publiccommunity[] = "public";
 
 /* statically allocated buffers for SNMP_CONCURRENT_REQUESTS */
 struct snmp_msg_pstat msg_input_list[SNMP_CONCURRENT_REQUESTS];
diff --git a/src/include/lwip/snmp_msg.h b/src/include/lwip/snmp_msg.h
index 3f65395d..44c5ff09 100644
--- a/src/include/lwip/snmp_msg.h
+++ b/src/include/lwip/snmp_msg.h
@@ -283,7 +283,7 @@ struct snmp_msg_trap
 /** Agent Version constant, 0 = v1 oddity */
 extern const s32_t snmp_version;
 /** Agent default "public" community string */
-extern const char snmp_publiccommunity[7];
+extern const char snmp_publiccommunity[];
 
 extern struct snmp_msg_trap trap_msg;