diff --git a/src/core/thread/address_resolver.cpp b/src/core/thread/address_resolver.cpp
index d2d5d0d6b..c39c1efe1 100644
--- a/src/core/thread/address_resolver.cpp
+++ b/src/core/thread/address_resolver.cpp
@@ -398,14 +398,13 @@ exit:
     return error;
 }
 
-otError AddressResolver::AddSnoopedCacheEntry(const Ip6::Address &aEid, Mac::ShortAddress aRloc16)
+void AddressResolver::AddSnoopedCacheEntry(const Ip6::Address &aEid, Mac::ShortAddress aRloc16)
 {
-    otError     error           = OT_ERROR_NONE;
     uint16_t    numNonEvictable = 0;
     CacheEntry *entry;
 
     entry = NewCacheEntry(/* aSnoopedEntry */ true);
-    VerifyOrExit(entry != NULL, error = OT_ERROR_NO_BUFS);
+    VerifyOrExit(entry != NULL, OT_NOOP);
 
     for (CacheEntry *snooped = mSnoopedList.GetHead(); snooped != NULL; snooped = snooped->GetNext())
     {
@@ -439,7 +438,7 @@ otError AddressResolver::AddSnoopedCacheEntry(const Ip6::Address &aEid, Mac::Sho
     LogCacheEntryChange(kEntryAdded, kReasonSnoop, *entry);
 
 exit:
-    return error;
+    return;
 }
 
 void AddressResolver::RestartAddressQueries(void)
diff --git a/src/core/thread/address_resolver.hpp b/src/core/thread/address_resolver.hpp
index 61381bba2..51f74fac2 100644
--- a/src/core/thread/address_resolver.hpp
+++ b/src/core/thread/address_resolver.hpp
@@ -146,11 +146,8 @@ public:
      * @param[in]  aEid               A reference to the EID.
      * @param[in]  aRloc16            The RLOC16 corresponding to @p aEid.
      *
-     * @retval OT_ERROR_NONE           Successfully adds the cache entry.
-     * @retval OT_ERROR_NO_BUFS        Insufficient buffer space available to add one cache entry.
-     *
      */
-    otError AddSnoopedCacheEntry(const Ip6::Address &aEid, Mac::ShortAddress aRloc16);
+    void AddSnoopedCacheEntry(const Ip6::Address &aEid, Mac::ShortAddress aRloc16);
 
     /**
      * This method returns the RLOC16 for a given EID, or initiates an Address Query if the mapping is not known.
diff --git a/src/core/thread/mesh_forwarder_ftd.cpp b/src/core/thread/mesh_forwarder_ftd.cpp
index 1c6ac1a45..c39a72f29 100644
--- a/src/core/thread/mesh_forwarder_ftd.cpp
+++ b/src/core/thread/mesh_forwarder_ftd.cpp
@@ -716,7 +716,7 @@ void MeshForwarder::UpdateRoutes(const uint8_t *     aFrame,
                 (aMeshDest.GetShort() == Get<Mac::Mac>().GetShortAddress() ||
                  Get<Mle::MleRouter>().IsMinimalChild(aMeshDest.GetShort())))
             {
-                IgnoreError(Get<AddressResolver>().AddSnoopedCacheEntry(ip6Header.GetSource(), aMeshSource.GetShort()));
+                Get<AddressResolver>().AddSnoopedCacheEntry(ip6Header.GetSource(), aMeshSource.GetShort());
             }
         }
     }