diff --git a/src/responder/nss/nss_cmd.c b/src/responder/nss/nss_cmd.c
index 956ee53..6f6a766 100644
--- a/src/responder/nss/nss_cmd.c
+++ b/src/responder/nss/nss_cmd.c
@@ -1131,6 +1131,22 @@ static errno_t nss_cmd_getsidbyid(struct cli_ctx *cli_ctx)
                         SSS_MC_NONE, nss_protocol_fill_sid);
 }
 
+static errno_t nss_cmd_getsidbyuid(struct cli_ctx *cli_ctx)
+{
+    const char *attrs[] = { SYSDB_SID_STR, NULL };
+
+    return nss_getby_id(cli_ctx, false, CACHE_REQ_OBJECT_BY_ID, attrs,
+                        SSS_MC_PASSWD, nss_protocol_fill_sid);
+}
+
+static errno_t nss_cmd_getsidbygid(struct cli_ctx *cli_ctx)
+{
+    const char *attrs[] = { SYSDB_SID_STR, NULL };
+
+    return nss_getby_id(cli_ctx, false, CACHE_REQ_OBJECT_BY_ID, attrs,
+                        SSS_MC_GROUP, nss_protocol_fill_sid);
+}
+
 static errno_t nss_cmd_getnamebysid(struct cli_ctx *cli_ctx)
 {
     return nss_getby_sid(cli_ctx, CACHE_REQ_OBJECT_BY_SID,
@@ -1222,6 +1238,8 @@ struct sss_cmd_table *get_nss_cmds(void)
         { SSS_NSS_ENDSERVENT, nss_cmd_endservent },
         { SSS_NSS_GETSIDBYNAME, nss_cmd_getsidbyname },
         { SSS_NSS_GETSIDBYID, nss_cmd_getsidbyid },
+	{ SSS_NSS_GETSIDBYUID, nss_cmd_getsidbyuid },
+	{ SSS_NSS_GETSIDBYGID, nss_cmd_getsidbygid },
         { SSS_NSS_GETNAMEBYSID, nss_cmd_getnamebysid },
         { SSS_NSS_GETIDBYSID, nss_cmd_getidbysid },
         { SSS_NSS_GETORIGBYNAME, nss_cmd_getorigbyname },
diff --git a/src/sss_client/idmap/sss_nss_idmap.c b/src/sss_client/idmap/sss_nss_idmap.c
index cbf8c11..e643011 100644
--- a/src/sss_client/idmap/sss_nss_idmap.c
+++ b/src/sss_client/idmap/sss_nss_idmap.c
@@ -246,6 +246,8 @@ static int sss_nss_getyyybyxxx(union input inp, enum sss_cli_command cmd,
 
         break;
     case SSS_NSS_GETSIDBYID:
+    case SSS_NSS_GETSIDBYUID:
+    case SSS_NSS_GETSIDBYGID:
         rd.len = sizeof(uint32_t);
         rd.data = &inp.id;
 
@@ -292,6 +294,8 @@ static int sss_nss_getyyybyxxx(union input inp, enum sss_cli_command cmd,
 
     switch(cmd) {
     case SSS_NSS_GETSIDBYID:
+    case SSS_NSS_GETSIDBYUID:
+    case SSS_NSS_GETSIDBYGID:
     case SSS_NSS_GETSIDBYNAME:
     case SSS_NSS_GETNAMEBYSID:
     case SSS_NSS_GETNAMEBYCERT:
@@ -414,6 +418,60 @@ int sss_nss_getsidbyid(uint32_t id, char **sid, enum sss_id_type *type)
     return sss_nss_getsidbyid_timeout(id, NO_TIMEOUT, sid, type);
 }
 
+int sss_nss_getsidbyuid_timeout(uint32_t uid, unsigned int timeout,
+                               char **sid, enum sss_id_type *type)
+{
+    int ret;
+    union input inp;
+    struct output out;
+
+    if (sid == NULL) {
+        return EINVAL;
+    }
+
+    inp.id = uid;
+
+    ret = sss_nss_getyyybyxxx(inp, SSS_NSS_GETSIDBYUID, timeout, &out);
+    if (ret == EOK) {
+        *sid = out.d.str;
+        *type = out.type;
+    }
+
+    return ret;
+}
+
+int sss_nss_getsidbyuid(uint32_t uid, char **sid, enum sss_id_type *type)
+{
+    return sss_nss_getsidbyuid_timeout(uid, NO_TIMEOUT, sid, type);
+}
+
+int sss_nss_getsidbygid_timeout(uint32_t gid, unsigned int timeout,
+                               char **sid, enum sss_id_type *type)
+{
+    int ret;
+    union input inp;
+    struct output out;
+
+    if (sid == NULL) {
+        return EINVAL;
+    }
+
+    inp.id = gid;
+
+    ret = sss_nss_getyyybyxxx(inp, SSS_NSS_GETSIDBYUID, timeout, &out);
+    if (ret == EOK) {
+        *sid = out.d.str;
+        *type = out.type;
+    }
+
+    return ret;
+}
+
+int sss_nss_getsidbygid(uint32_t gid, char **sid, enum sss_id_type *type)
+{
+    return sss_nss_getsidbygid_timeout(gid, NO_TIMEOUT, sid, type);
+}
+
 int sss_nss_getnamebysid_timeout(const char *sid, unsigned int timeout,
                                  char **fq_name, enum sss_id_type *type)
 {
diff --git a/src/sss_client/idmap/sss_nss_idmap.h b/src/sss_client/idmap/sss_nss_idmap.h
index 125e72a..92d6672 100644
--- a/src/sss_client/idmap/sss_nss_idmap.h
+++ b/src/sss_client/idmap/sss_nss_idmap.h
@@ -79,6 +79,32 @@ int sss_nss_getsidbyname(const char *fq_name, char **sid,
 int sss_nss_getsidbyid(uint32_t id, char **sid, enum sss_id_type *type);
 
 /**
+ * @brief Find SID by a POSIX UID
+ *
+ * @param[in] id       GID
+ * @param[out] sid     String representation of the SID of the requested user
+ *                     or group, must be freed by the caller
+ * @param[out] type    Type of the object related to the given ID
+ *
+ * @return
+ *  - see #sss_nss_getsidbyname
+ */
+int sss_nss_getsidbyuid(uint32_t id, char **sid, enum sss_id_type *type);
+
+/**
+ * @brief Find SID by a POSIX GID
+ *
+ * @param[in] id       GID
+ * @param[out] sid     String representation of the SID of the requested user
+ *                     or group, must be freed by the caller
+ * @param[out] type    Type of the object related to the given ID
+ *
+ * @return
+ *  - see #sss_nss_getsidbyname
+ */
+int sss_nss_getsidbygid(uint32_t id, char **sid, enum sss_id_type *type);
+
+/**
  * @brief Return the fully qualified name for the given SID
  *
  * @param[in] sid      String representation of the SID
diff --git a/src/sss_client/sss_cli.h b/src/sss_client/sss_cli.h
index 34eee58..b10cc03 100644
--- a/src/sss_client/sss_cli.h
+++ b/src/sss_client/sss_cli.h
@@ -272,6 +272,14 @@ SSS_NSS_GETLISTBYCERT = 0x0117, /**< Takes the zero terminated string
                                      of a X509 certificate and returns a list
                                      of zero terminated fully qualified names
                                      of the related objects. */
+SSS_NSS_GETSIDBYUID   = 0x0118, /**< Takes an unsigned 32bit integer (POSIX UID)
+				     and reurn the zero terminated string
+				     representation of the SID of the object
+				     with the given UID. */
+SSS_NSS_GETSIDBYGID   = 0x0119, /**< Takes an unsigned 32bit integer (POSIX GID)
+				     and reurn the zero terminated string
+				     representation of the SID of the object
+				     with the given UID. */
 };
 
 /**