diff --git a/DESCRIPTION b/DESCRIPTION
index 46ba078dd2..40bd0576c3 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -96,6 +96,8 @@ Language: en-US
 LazyData: true
 Roxygen: list(markdown = TRUE, packages = c("roxy.shinylive"))
 RoxygenNote: 7.3.3
+Remotes:
+    insightsengineering/teal.slice@main
 Collate:
     'TealAppDriver.R'
     'after.R'
diff --git a/R/checkmate.R b/R/checkmate.R
index a6463c175e..7e754d2e51 100644
--- a/R/checkmate.R
+++ b/R/checkmate.R
@@ -12,7 +12,7 @@ check_reactive <- function(x, null.ok = FALSE) { # nolint: object_name_linter.
       paste0(cl, collapse = "','")
     ))
   }
-  return(TRUE)
+  TRUE
 }
 #' @rdname check_reactive
 test_reactive <- function(x, null.ok = FALSE) { # nolint: object_name_linter.
diff --git a/R/module_transform_data.R b/R/module_transform_data.R
index 3c9daa7d2f..a9558ebd7f 100644
--- a/R/module_transform_data.R
+++ b/R/module_transform_data.R
@@ -25,7 +25,7 @@ ui_transform_teal_data <- function(id, transformators, class = "well") {
     transformators <- list(transformators)
   }
   checkmate::assert_list(transformators, "teal_transform_module")
-  names(transformators) <- sprintf("transform_%d", seq_len(length(transformators)))
+  names(transformators) <- sprintf("transform_%d", seq_along(transformators))
 
   lapply(
     names(transformators),
@@ -75,7 +75,7 @@ srv_transform_teal_data <- function(id, data, transformators, modules = NULL, is
     transformators <- list(transformators)
   }
   checkmate::assert_list(transformators, "teal_transform_module", null.ok = TRUE)
-  names(transformators) <- sprintf("transform_%d", seq_len(length(transformators)))
+  names(transformators) <- sprintf("transform_%d", seq_along(transformators))
 
   moduleServer(id, function(input, output, session) {
     module_output <- Reduce(
diff --git a/R/teal_slices.R b/R/teal_slices.R
index d4547b4eff..af234cb115 100644
--- a/R/teal_slices.R
+++ b/R/teal_slices.R
@@ -123,43 +123,6 @@ teal_slices <- function(...,
   })
 }
 
-
-#' @rdname teal_slices
-#' @export
-#' @keywords internal
-#'
-as.teal_slices <- function(x) { # nolint: object_name.
-  checkmate::assert_list(x)
-  lapply(x, checkmate::assert_list, names = "named", .var.name = "list element")
-
-  attrs <- attributes(unclass(x))
-  ans <- lapply(x, function(x) if (is.teal_slice(x)) x else as.teal_slice(x))
-  do.call(teal_slices, c(ans, attrs))
-}
-
-
-#' @rdname teal_slices
-#' @export
-#' @keywords internal
-#'
-c.teal_slices <- function(...) {
-  x <- list(...)
-  checkmate::assert_true(all(vapply(x, is.teal_slices, logical(1L))), .var.name = "all arguments are teal_slices")
-
-  all_attributes <- lapply(x, attributes)
-  all_attributes <- coalesce_r(all_attributes)
-  all_attributes <- all_attributes[names(all_attributes) != "class"]
-
-  do.call(
-    teal_slices,
-    c(
-      unique(unlist(x, recursive = FALSE)),
-      all_attributes
-    )
-  )
-}
-
-
 #' Deep copy `teal_slices`
 #'
 #' it's important to create a new copy of `teal_slices` when
@@ -179,3 +142,26 @@ deep_copy_filter <- function(filter) {
     filter_copy
   })
 }
+
+
+#' Copy functions to `teal` namespace
+#'
+#' Useful when we require function from other namespace where this function
+#' calls other functions from `teal` namespace (see `as.teal_slices`, `c.teal_slices`).
+#' @keywords internal
+.copy_to_teal <- function(fun) {
+  environment(fun) <- getNamespace("teal")
+  fun
+}
+
+#' @rdname teal_slices
+#' @export
+#' @keywords internal
+#'
+as.teal_slices <- .copy_to_teal(teal.slice::as.teal_slices) # nolint: object_name_linter.
+
+#' @rdname teal_slices
+#' @export
+#' @keywords internal
+#'
+c.teal_slices <- .copy_to_teal(utils::getS3method("c", "teal_slices", envir = getNamespace("teal.slice")))
diff --git a/man/dot-copy_to_teal.Rd b/man/dot-copy_to_teal.Rd
new file mode 100644
index 0000000000..57b83cffb8
--- /dev/null
+++ b/man/dot-copy_to_teal.Rd
@@ -0,0 +1,13 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/teal_slices.R
+\name{.copy_to_teal}
+\alias{.copy_to_teal}
+\title{Copy functions to \code{teal} namespace}
+\usage{
+.copy_to_teal(fun)
+}
+\description{
+Useful when we require function from other namespace where this function
+calls other functions from \code{teal} namespace (see \code{as.teal_slices}, \code{c.teal_slices}).
+}
+\keyword{internal}
diff --git a/tests/testthat/test-teal_slices.R b/tests/testthat/test-teal_slices.R
index a64f518639..7bcc337f23 100644
--- a/tests/testthat/test-teal_slices.R
+++ b/tests/testthat/test-teal_slices.R
@@ -111,10 +111,6 @@ testthat::test_that(
   }
 )
 
-
-# from different file
-
-
 testthat::test_that("teal_slices mapping should be an empty list or a named list or missing", {
   testthat::expect_no_error(
     teal_slices(
@@ -156,3 +152,52 @@ testthat::test_that("teal_slices mapping should be an empty list or a named list
     "Assertion.+failed"
   )
 })
+
+testthat::test_that("c.teal_slices combines mapping of teal_slices objects", {
+  tss1 <- teal_slices(
+    teal.slice::teal_slice(dataname = "data1", varname = "var1", id = "test1"),
+    module_specific = TRUE,
+    mapping = list(module1 = "test1")
+  )
+  tss2 <- teal_slices(
+    teal.slice::teal_slice(dataname = "data2", varname = "var2", id = "test2"),
+    module_specific = TRUE,
+    mapping = list(module2 = "test2")
+  )
+  testthat::expect_identical(
+    c(tss1, tss2),
+    teal_slices(
+      tss1[[1]], tss2[[1]],
+      module_specific = TRUE,
+      mapping = list(
+        module1 = "test1",
+        module2 = "test2"
+      )
+    )
+  )
+})
+
+testthat::test_that("c.teal_slices combines mapping of two equal slices objects but ignores adding duplicated one", {
+  tss1 <- teal_slices(
+    teal.slice::teal_slice(dataname = "data1", varname = "var1", id = "test1"),
+    module_specific = TRUE,
+    mapping = list(module1 = "test1")
+  )
+  tss2 <- teal_slices(
+    teal.slice::teal_slice(dataname = "data1", varname = "var1", id = "test1"),
+    module_specific = TRUE,
+    mapping = list(module2 = "test1")
+  )
+
+  testthat::expect_identical(
+    c(tss1, tss2),
+    teal_slices(
+      tss1[[1]],
+      module_specific = TRUE,
+      mapping = list(
+        module1 = "test1",
+        module2 = "test1"
+      )
+    )
+  )
+})