diff --git a/src/intset.c b/src/intset.c
index bfd3307d..5a062102 100644
--- a/src/intset.c
+++ b/src/intset.c
@@ -222,6 +222,11 @@ uint32_t intsetLen(intset *is) {
     return is->length;
 }
 
+/* Return intset size in bytes. */
+size_t intsetSize(intset *is) {
+    return sizeof(intset)+is->length*is->encoding;
+}
+
 #ifdef INTSET_TEST_MAIN
 #include <sys/time.h>
 
diff --git a/src/intset.h b/src/intset.h
index 10d49d2e..6a504001 100644
--- a/src/intset.h
+++ b/src/intset.h
@@ -15,5 +15,6 @@ uint8_t intsetFind(intset *is, int64_t value);
 int64_t intsetRandom(intset *is);
 uint8_t intsetGet(intset *is, uint32_t pos, int64_t *value);
 uint32_t intsetLen(intset *is);
+size_t intsetSize(intset *is);
 
 #endif // __INTSET_H
diff --git a/src/ziplist.c b/src/ziplist.c
index 1d7fee9f..c1ee1c5f 100644
--- a/src/ziplist.c
+++ b/src/ziplist.c
@@ -732,8 +732,8 @@ unsigned int ziplistLen(unsigned char *zl) {
     return len;
 }
 
-/* Return size in bytes of ziplist. */
-unsigned int ziplistSize(unsigned char *zl) {
+/* Return ziplist size in bytes. */
+size_t ziplistSize(unsigned char *zl) {
     return ZIPLIST_BYTES(zl);
 }
 
diff --git a/src/ziplist.h b/src/ziplist.h
index 31125725..1ad95bbf 100644
--- a/src/ziplist.h
+++ b/src/ziplist.h
@@ -12,4 +12,4 @@ unsigned char *ziplistDelete(unsigned char *zl, unsigned char **p);
 unsigned char *ziplistDeleteRange(unsigned char *zl, unsigned int index, unsigned int num);
 unsigned int ziplistCompare(unsigned char *p, unsigned char *s, unsigned int slen);
 unsigned int ziplistLen(unsigned char *zl);
-unsigned int ziplistSize(unsigned char *zl);
+size_t ziplistSize(unsigned char *zl);
diff --git a/src/zipmap.c b/src/zipmap.c
index 2e2cbc3b..cc7586cf 100644
--- a/src/zipmap.c
+++ b/src/zipmap.c
@@ -144,7 +144,7 @@ static unsigned char *zipmapLookupRaw(unsigned char *zm, unsigned char *key, uns
         /* Match or skip the key */
         l = zipmapDecodeLength(p);
         llen = zipmapEncodeLength(NULL,l);
-        if (k == NULL && l == klen && !memcmp(p+llen,key,l)) {
+        if (key != NULL && k == NULL && l == klen && !memcmp(p+llen,key,l)) {
             /* Only return when the user doesn't care
              * for the total length of the zipmap. */
             if (totlen != NULL) {
@@ -360,6 +360,13 @@ unsigned int zipmapLen(unsigned char *zm) {
     return len;
 }
 
+/* Return zipmap size in bytes. */
+size_t zipmapSize(unsigned char *zm) {
+    unsigned int totlen;
+    zipmapLookupRaw(zm,NULL,0,&totlen);
+    return totlen;
+}
+
 #ifdef ZIPMAP_TEST_MAIN
 
 void zipmapRepr(unsigned char *p) {
diff --git a/src/zipmap.h b/src/zipmap.h
index 089472ed..ae800030 100644
--- a/src/zipmap.h
+++ b/src/zipmap.h
@@ -43,5 +43,6 @@ unsigned char *zipmapNext(unsigned char *zm, unsigned char **key, unsigned int *
 int zipmapGet(unsigned char *zm, unsigned char *key, unsigned int klen, unsigned char **value, unsigned int *vlen);
 int zipmapExists(unsigned char *zm, unsigned char *key, unsigned int klen);
 unsigned int zipmapLen(unsigned char *zm);
+size_t zipmapSize(unsigned char *zm);
 
 #endif