diff --git a/src/posix/platform/infra_if.cpp b/src/posix/platform/infra_if.cpp
index 91ab6d5d7..0bbe6f42a 100644
--- a/src/posix/platform/infra_if.cpp
+++ b/src/posix/platform/infra_if.cpp
@@ -258,7 +258,9 @@ bool InfraNetif::IsRunning(void) const
     VerifyOrDie(sock != -1, OT_EXIT_ERROR_ERRNO);
 
     memset(&ifReq, 0, sizeof(ifReq));
-    strncpy(ifReq.ifr_name, mInfraIfName, sizeof(ifReq.ifr_name));
+    static_assert(sizeof(ifReq.ifr_name) >= sizeof(mInfraIfName), "mInfraIfName is not of appropriate size.");
+    strcpy(ifReq.ifr_name, mInfraIfName);
+
     VerifyOrDie(ioctl(sock, SIOCGIFFLAGS, &ifReq) != -1, OT_EXIT_ERROR_ERRNO);
 
     close(sock);
@@ -274,7 +276,7 @@ void InfraNetif::Init(otInstance *aInstance, const char *aIfName)
     VerifyOrExit(aIfName != nullptr);
 
     VerifyOrDie(strnlen(aIfName, sizeof(mInfraIfName)) <= sizeof(mInfraIfName) - 1, OT_EXIT_INVALID_ARGUMENTS);
-    strncpy(mInfraIfName, aIfName, sizeof(mInfraIfName));
+    strcpy(mInfraIfName, aIfName);
 
     // Initializes the infra interface.
     ifIndex = if_nametoindex(aIfName);