diff --git a/src/defrag.c b/src/defrag.c
index 8867b301f..7d375305c 100644
--- a/src/defrag.c
+++ b/src/defrag.c
@@ -482,8 +482,7 @@ long scanLaterList(robj *ob, unsigned long *cursor, monotime endtime) {
     quicklistNode *node;
     long iterations = 0;
     int bookmark_failed = 0;
-    if (ob->type != OBJ_LIST || ob->encoding != OBJ_ENCODING_QUICKLIST)
-        return 0;
+    serverAssert(ob->type == OBJ_LIST && ob->encoding == OBJ_ENCODING_QUICKLIST);
 
     if (*cursor == 0) {
         /* if cursor is 0, we start new iteration */
@@ -532,8 +531,7 @@ void scanLaterZsetCallback(void *privdata, const dictEntry *_de) {
 }
 
 void scanLaterZset(robj *ob, unsigned long *cursor) {
-    if (ob->type != OBJ_ZSET || ob->encoding != OBJ_ENCODING_SKIPLIST)
-        return;
+    serverAssert(ob->type == OBJ_ZSET && ob->encoding == OBJ_ENCODING_SKIPLIST);
     zset *zs = (zset*)ob->ptr;
     dict *d = zs->dict;
     scanLaterZsetData data = {zs};
@@ -549,8 +547,7 @@ void scanCallbackCountScanned(void *privdata, const dictEntry *de) {
 }
 
 void scanLaterSet(robj *ob, unsigned long *cursor) {
-    if (ob->type != OBJ_SET || ob->encoding != OBJ_ENCODING_HT)
-        return;
+    serverAssert(ob->type == OBJ_SET && ob->encoding == OBJ_ENCODING_HT);
     dict *d = ob->ptr;
     dictDefragFunctions defragfns = {
         .defragAlloc = activeDefragAlloc,
@@ -560,8 +557,7 @@ void scanLaterSet(robj *ob, unsigned long *cursor) {
 }
 
 void scanLaterHash(robj *ob, unsigned long *cursor) {
-    if (ob->type != OBJ_HASH || ob->encoding != OBJ_ENCODING_HT)
-        return;
+    serverAssert(ob->type == OBJ_HASH && ob->encoding == OBJ_ENCODING_HT);
     dict *d = ob->ptr;
     dictDefragFunctions defragfns = {
         .defragAlloc = activeDefragAlloc,
@@ -656,10 +652,7 @@ int scanLaterStreamListpacks(robj *ob, unsigned long *cursor, monotime endtime)
     static unsigned char next[sizeof(streamID)];
     raxIterator ri;
     long iterations = 0;
-    if (ob->type != OBJ_STREAM || ob->encoding != OBJ_ENCODING_STREAM) {
-        *cursor = 0;
-        return 0;
-    }
+    serverAssert(ob->type == OBJ_STREAM && ob->encoding == OBJ_ENCODING_STREAM);
 
     stream *s = ob->ptr;
     raxStart(&ri,s->rax);
@@ -1005,22 +998,22 @@ void defragPubsubScanCallback(void *privdata, const dictEntry *de) {
 int defragLaterItem(dictEntry *de, unsigned long *cursor, monotime endtime, int dbid) {
     if (de) {
         robj *ob = dictGetVal(de);
-        if (ob->type == OBJ_LIST) {
+        if (ob->type == OBJ_LIST && ob->encoding == OBJ_ENCODING_QUICKLIST) {
             return scanLaterList(ob, cursor, endtime);
-        } else if (ob->type == OBJ_SET) {
+        } else if (ob->type == OBJ_SET && ob->encoding == OBJ_ENCODING_HT) {
             scanLaterSet(ob, cursor);
-        } else if (ob->type == OBJ_ZSET) {
+        } else if (ob->type == OBJ_ZSET && ob->encoding == OBJ_ENCODING_SKIPLIST) {
             scanLaterZset(ob, cursor);
-        } else if (ob->type == OBJ_HASH) {
+        } else if (ob->type == OBJ_HASH && ob->encoding == OBJ_ENCODING_HT) {
             scanLaterHash(ob, cursor);
-        } else if (ob->type == OBJ_STREAM) {
+        } else if (ob->type == OBJ_STREAM && ob->encoding == OBJ_ENCODING_STREAM) {
             return scanLaterStreamListpacks(ob, cursor, endtime);
         } else if (ob->type == OBJ_MODULE) {
             robj keyobj;
             initStaticStringObject(keyobj, dictGetKey(de));
             return moduleLateDefrag(&keyobj, ob, cursor, endtime, dbid);
         } else {
-            *cursor = 0; /* object type may have changed since we schedule it for later */
+            *cursor = 0; /* object type/encoding may have changed since we schedule it for later */
         }
     } else {
         *cursor = 0; /* object may have been deleted already */