diff --git a/DESCRIPTION b/DESCRIPTION
index cb09e72..ec0c7b3 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -19,7 +19,7 @@ Imports:
     diffobj (>= 0.3.4),
     glue,
     methods,
-    rlang (>= 1.0.0)
+    rlang (>= 1.1.0)
 Suggests:
     R6,
     S7,
diff --git a/NEWS.md b/NEWS.md
index 86a7e8e..6cfec56 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,6 @@
 # waldo (development version)
 
+* `compare()` now gives informative errors if you misspecify the argument types (#181)
 * waldo gains basic support for S7 objects (#200).
 * `as_map()` now preserves attributes (#185).
 * `compare()` can now distinguish between objects that differ only in the value of their S4 bit (#189).
diff --git a/R/compare.R b/R/compare.R
index 3ccae24..1e7c478 100644
--- a/R/compare.R
+++ b/R/compare.R
@@ -92,7 +92,7 @@
 #'   this is R's default behaviour. Use `FALSE` when specifically concerned
 #'   with the encoding, not just the value of the string.
 #' @param list_as_map Compare lists as if they are mappings between names and
-#'   values. Concretely, this drops `NULLs` in both objects and sorts named
+#'   values. Concretely, this drops `NULL`s in both objects and sorts named
 #'   components.
 #' @param quote_strings Should strings be surrounded by quotes? If `FALSE`,
 #'   only side-by-side and line-by-line comparisons will be used, and there's
@@ -137,6 +137,20 @@ compare <- function(x, y, ...,
                     quote_strings = TRUE
                     ) {
 
+  check_string(x_arg)
+  check_string(y_arg)
+  check_number_decimal(tolerance, allow_null = TRUE, min = 0)
+  check_number_whole(max_diffs, min = 1, allow_infinite = TRUE)
+  check_bool(ignore_srcref)
+  if (!isTRUE(ignore_attr) && !is.character(ignore_attr)) {
+    stop_input_type(ignore_attr, "a TRUE or a character vector")
+  }
+  check_bool(ignore_encoding)
+  check_bool(ignore_function_env)
+  check_bool(ignore_formula_env)
+  check_bool(list_as_map)
+  check_bool(quote_strings)
+
   opts <- compare_opts(
     ...,
     tolerance = tolerance,
diff --git a/R/import-standalone-obj-type.R b/R/import-standalone-obj-type.R
new file mode 100644
index 0000000..47268d6
--- /dev/null
+++ b/R/import-standalone-obj-type.R
@@ -0,0 +1,364 @@
+# Standalone file: do not edit by hand
+# Source: https://github.com/r-lib/rlang/blob/HEAD/R/standalone-obj-type.R
+# Generated by: usethis::use_standalone("r-lib/rlang", "obj-type")
+# ----------------------------------------------------------------------
+#
+# ---
+# repo: r-lib/rlang
+# file: standalone-obj-type.R
+# last-updated: 2024-02-14
+# license: https://unlicense.org
+# imports: rlang (>= 1.1.0)
+# ---
+#
+# ## Changelog
+#
+# 2024-02-14:
+# - `obj_type_friendly()` now works for S7 objects.
+#
+# 2023-05-01:
+# - `obj_type_friendly()` now only displays the first class of S3 objects.
+#
+# 2023-03-30:
+# - `stop_input_type()` now handles `I()` input literally in `arg`.
+#
+# 2022-10-04:
+# - `obj_type_friendly(value = TRUE)` now shows numeric scalars
+#   literally.
+# - `stop_friendly_type()` now takes `show_value`, passed to
+#   `obj_type_friendly()` as the `value` argument.
+#
+# 2022-10-03:
+# - Added `allow_na` and `allow_null` arguments.
+# - `NULL` is now backticked.
+# - Better friendly type for infinities and `NaN`.
+#
+# 2022-09-16:
+# - Unprefixed usage of rlang functions with `rlang::` to
+#   avoid onLoad issues when called from rlang (#1482).
+#
+# 2022-08-11:
+# - Prefixed usage of rlang functions with `rlang::`.
+#
+# 2022-06-22:
+# - `friendly_type_of()` is now `obj_type_friendly()`.
+# - Added `obj_type_oo()`.
+#
+# 2021-12-20:
+# - Added support for scalar values and empty vectors.
+# - Added `stop_input_type()`
+#
+# 2021-06-30:
+# - Added support for missing arguments.
+#
+# 2021-04-19:
+# - Added support for matrices and arrays (#141).
+# - Added documentation.
+# - Added changelog.
+#
+# nocov start
+
+#' Return English-friendly type
+#' @param x Any R object.
+#' @param value Whether to describe the value of `x`. Special values
+#'   like `NA` or `""` are always described.
+#' @param length Whether to mention the length of vectors and lists.
+#' @return A string describing the type. Starts with an indefinite
+#'   article, e.g. "an integer vector".
+#' @noRd
+obj_type_friendly <- function(x, value = TRUE) {
+  if (is_missing(x)) {
+    return("absent")
+  }
+
+  if (is.object(x)) {
+    if (inherits(x, "quosure")) {
+      type <- "quosure"
+    } else {
+      type <- class(x)[[1L]]
+    }
+    return(sprintf("a <%s> object", type))
+  }
+
+  if (!is_vector(x)) {
+    return(.rlang_as_friendly_type(typeof(x)))
+  }
+
+  n_dim <- length(dim(x))
+
+  if (!n_dim) {
+    if (!is_list(x) && length(x) == 1) {
+      if (is_na(x)) {
+        return(switch(
+          typeof(x),
+          logical = "`NA`",
+          integer = "an integer `NA`",
+          double =
+            if (is.nan(x)) {
+              "`NaN`"
+            } else {
+              "a numeric `NA`"
+            },
+          complex = "a complex `NA`",
+          character = "a character `NA`",
+          .rlang_stop_unexpected_typeof(x)
+        ))
+      }
+
+      show_infinites <- function(x) {
+        if (x > 0) {
+          "`Inf`"
+        } else {
+          "`-Inf`"
+        }
+      }
+      str_encode <- function(x, width = 30, ...) {
+        if (nchar(x) > width) {
+          x <- substr(x, 1, width - 3)
+          x <- paste0(x, "...")
+        }
+        encodeString(x, ...)
+      }
+
+      if (value) {
+        if (is.numeric(x) && is.infinite(x)) {
+          return(show_infinites(x))
+        }
+
+        if (is.numeric(x) || is.complex(x)) {
+          number <- as.character(round(x, 2))
+          what <- if (is.complex(x)) "the complex number" else "the number"
+          return(paste(what, number))
+        }
+
+        return(switch(
+          typeof(x),
+          logical = if (x) "`TRUE`" else "`FALSE`",
+          character = {
+            what <- if (nzchar(x)) "the string" else "the empty string"
+            paste(what, str_encode(x, quote = "\""))
+          },
+          raw = paste("the raw value", as.character(x)),
+          .rlang_stop_unexpected_typeof(x)
+        ))
+      }
+
+      return(switch(
+        typeof(x),
+        logical = "a logical value",
+        integer = "an integer",
+        double = if (is.infinite(x)) show_infinites(x) else "a number",
+        complex = "a complex number",
+        character = if (nzchar(x)) "a string" else "\"\"",
+        raw = "a raw value",
+        .rlang_stop_unexpected_typeof(x)
+      ))
+    }
+
+    if (length(x) == 0) {
+      return(switch(
+        typeof(x),
+        logical = "an empty logical vector",
+        integer = "an empty integer vector",
+        double = "an empty numeric vector",
+        complex = "an empty complex vector",
+        character = "an empty character vector",
+        raw = "an empty raw vector",
+        list = "an empty list",
+        .rlang_stop_unexpected_typeof(x)
+      ))
+    }
+  }
+
+  vec_type_friendly(x)
+}
+
+vec_type_friendly <- function(x, length = FALSE) {
+  if (!is_vector(x)) {
+    abort("`x` must be a vector.")
+  }
+  type <- typeof(x)
+  n_dim <- length(dim(x))
+
+  add_length <- function(type) {
+    if (length && !n_dim) {
+      paste0(type, sprintf(" of length %s", length(x)))
+    } else {
+      type
+    }
+  }
+
+  if (type == "list") {
+    if (n_dim < 2) {
+      return(add_length("a list"))
+    } else if (is.data.frame(x)) {
+      return("a data frame")
+    } else if (n_dim == 2) {
+      return("a list matrix")
+    } else {
+      return("a list array")
+    }
+  }
+
+  type <- switch(
+    type,
+    logical = "a logical %s",
+    integer = "an integer %s",
+    numeric = ,
+    double = "a double %s",
+    complex = "a complex %s",
+    character = "a character %s",
+    raw = "a raw %s",
+    type = paste0("a ", type, " %s")
+  )
+
+  if (n_dim < 2) {
+    kind <- "vector"
+  } else if (n_dim == 2) {
+    kind <- "matrix"
+  } else {
+    kind <- "array"
+  }
+  out <- sprintf(type, kind)
+
+  if (n_dim >= 2) {
+    out
+  } else {
+    add_length(out)
+  }
+}
+
+.rlang_as_friendly_type <- function(type) {
+  switch(
+    type,
+
+    list = "a list",
+
+    NULL = "`NULL`",
+    environment = "an environment",
+    externalptr = "a pointer",
+    weakref = "a weak reference",
+    S4 = "an S4 object",
+
+    name = ,
+    symbol = "a symbol",
+    language = "a call",
+    pairlist = "a pairlist node",
+    expression = "an expression vector",
+
+    char = "an internal string",
+    promise = "an internal promise",
+    ... = "an internal dots object",
+    any = "an internal `any` object",
+    bytecode = "an internal bytecode object",
+
+    primitive = ,
+    builtin = ,
+    special = "a primitive function",
+    closure = "a function",
+
+    type
+  )
+}
+
+.rlang_stop_unexpected_typeof <- function(x, call = caller_env()) {
+  abort(
+    sprintf("Unexpected type <%s>.", typeof(x)),
+    call = call
+  )
+}
+
+#' Return OO type
+#' @param x Any R object.
+#' @return One of `"bare"` (for non-OO objects), `"S3"`, `"S4"`,
+#'   `"R6"`, or `"S7"`.
+#' @noRd
+obj_type_oo <- function(x) {
+  if (!is.object(x)) {
+    return("bare")
+  }
+
+  class <- inherits(x, c("R6", "S7_object"), which = TRUE)
+
+  if (class[[1]]) {
+    "R6"
+  } else if (class[[2]]) {
+    "S7"
+  } else if (isS4(x)) {
+    "S4"
+  } else {
+    "S3"
+  }
+}
+
+#' @param x The object type which does not conform to `what`. Its
+#'   `obj_type_friendly()` is taken and mentioned in the error message.
+#' @param what The friendly expected type as a string. Can be a
+#'   character vector of expected types, in which case the error
+#'   message mentions all of them in an "or" enumeration.
+#' @param show_value Passed to `value` argument of `obj_type_friendly()`.
+#' @param ... Arguments passed to [abort()].
+#' @inheritParams args_error_context
+#' @noRd
+stop_input_type <- function(x,
+                            what,
+                            ...,
+                            allow_na = FALSE,
+                            allow_null = FALSE,
+                            show_value = TRUE,
+                            arg = caller_arg(x),
+                            call = caller_env()) {
+  # From standalone-cli.R
+  cli <- env_get_list(
+    nms = c("format_arg", "format_code"),
+    last = topenv(),
+    default = function(x) sprintf("`%s`", x),
+    inherit = TRUE
+  )
+
+  if (allow_na) {
+    what <- c(what, cli$format_code("NA"))
+  }
+  if (allow_null) {
+    what <- c(what, cli$format_code("NULL"))
+  }
+  if (length(what)) {
+    what <- oxford_comma(what)
+  }
+  if (inherits(arg, "AsIs")) {
+    format_arg <- identity
+  } else {
+    format_arg <- cli$format_arg
+  }
+
+  message <- sprintf(
+    "%s must be %s, not %s.",
+    format_arg(arg),
+    what,
+    obj_type_friendly(x, value = show_value)
+  )
+
+  abort(message, ..., call = call, arg = arg)
+}
+
+oxford_comma <- function(chr, sep = ", ", final = "or") {
+  n <- length(chr)
+
+  if (n < 2) {
+    return(chr)
+  }
+
+  head <- chr[seq_len(n - 1)]
+  last <- chr[n]
+
+  head <- paste(head, collapse = sep)
+
+  # Write a or b. But a, b, or c.
+  if (n > 2) {
+    paste0(head, sep, final, " ", last)
+  } else {
+    paste0(head, " ", final, " ", last)
+  }
+}
+
+# nocov end
diff --git a/R/import-standalone-types-check.R b/R/import-standalone-types-check.R
new file mode 100644
index 0000000..ef8c5a1
--- /dev/null
+++ b/R/import-standalone-types-check.R
@@ -0,0 +1,554 @@
+# Standalone file: do not edit by hand
+# Source: https://github.com/r-lib/rlang/blob/HEAD/R/standalone-types-check.R
+# Generated by: usethis::use_standalone("r-lib/rlang", "types-check")
+# ----------------------------------------------------------------------
+#
+# ---
+# repo: r-lib/rlang
+# file: standalone-types-check.R
+# last-updated: 2023-03-13
+# license: https://unlicense.org
+# dependencies: standalone-obj-type.R
+# imports: rlang (>= 1.1.0)
+# ---
+#
+# ## Changelog
+#
+# 2024-08-15:
+# - `check_character()` gains an `allow_na` argument (@martaalcalde, #1724)
+#
+# 2023-03-13:
+# - Improved error messages of number checkers (@teunbrand)
+# - Added `allow_infinite` argument to `check_number_whole()` (@mgirlich).
+# - Added `check_data_frame()` (@mgirlich).
+#
+# 2023-03-07:
+# - Added dependency on rlang (>= 1.1.0).
+#
+# 2023-02-15:
+# - Added `check_logical()`.
+#
+# - `check_bool()`, `check_number_whole()`, and
+#   `check_number_decimal()` are now implemented in C.
+#
+# - For efficiency, `check_number_whole()` and
+#   `check_number_decimal()` now take a `NULL` default for `min` and
+#   `max`. This makes it possible to bypass unnecessary type-checking
+#   and comparisons in the default case of no bounds checks.
+#
+# 2022-10-07:
+# - `check_number_whole()` and `_decimal()` no longer treat
+#   non-numeric types such as factors or dates as numbers.  Numeric
+#   types are detected with `is.numeric()`.
+#
+# 2022-10-04:
+# - Added `check_name()` that forbids the empty string.
+#   `check_string()` allows the empty string by default.
+#
+# 2022-09-28:
+# - Removed `what` arguments.
+# - Added `allow_na` and `allow_null` arguments.
+# - Added `allow_decimal` and `allow_infinite` arguments.
+# - Improved errors with absent arguments.
+#
+#
+# 2022-09-16:
+# - Unprefixed usage of rlang functions with `rlang::` to
+#   avoid onLoad issues when called from rlang (#1482).
+#
+# 2022-08-11:
+# - Added changelog.
+#
+# nocov start
+
+# Scalars -----------------------------------------------------------------
+
+.standalone_types_check_dot_call <- .Call
+
+check_bool <- function(x,
+                       ...,
+                       allow_na = FALSE,
+                       allow_null = FALSE,
+                       arg = caller_arg(x),
+                       call = caller_env()) {
+  if (!missing(x) && .standalone_types_check_dot_call(ffi_standalone_is_bool_1.0.7, x, allow_na, allow_null)) {
+    return(invisible(NULL))
+  }
+
+  stop_input_type(
+    x,
+    c("`TRUE`", "`FALSE`"),
+    ...,
+    allow_na = allow_na,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_string <- function(x,
+                         ...,
+                         allow_empty = TRUE,
+                         allow_na = FALSE,
+                         allow_null = FALSE,
+                         arg = caller_arg(x),
+                         call = caller_env()) {
+  if (!missing(x)) {
+    is_string <- .rlang_check_is_string(
+      x,
+      allow_empty = allow_empty,
+      allow_na = allow_na,
+      allow_null = allow_null
+    )
+    if (is_string) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a single string",
+    ...,
+    allow_na = allow_na,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+.rlang_check_is_string <- function(x,
+                                   allow_empty,
+                                   allow_na,
+                                   allow_null) {
+  if (is_string(x)) {
+    if (allow_empty || !is_string(x, "")) {
+      return(TRUE)
+    }
+  }
+
+  if (allow_null && is_null(x)) {
+    return(TRUE)
+  }
+
+  if (allow_na && (identical(x, NA) || identical(x, na_chr))) {
+    return(TRUE)
+  }
+
+  FALSE
+}
+
+check_name <- function(x,
+                       ...,
+                       allow_null = FALSE,
+                       arg = caller_arg(x),
+                       call = caller_env()) {
+  if (!missing(x)) {
+    is_string <- .rlang_check_is_string(
+      x,
+      allow_empty = FALSE,
+      allow_na = FALSE,
+      allow_null = allow_null
+    )
+    if (is_string) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a valid name",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+IS_NUMBER_true <- 0
+IS_NUMBER_false <- 1
+IS_NUMBER_oob <- 2
+
+check_number_decimal <- function(x,
+                                 ...,
+                                 min = NULL,
+                                 max = NULL,
+                                 allow_infinite = TRUE,
+                                 allow_na = FALSE,
+                                 allow_null = FALSE,
+                                 arg = caller_arg(x),
+                                 call = caller_env()) {
+  if (missing(x)) {
+    exit_code <- IS_NUMBER_false
+  } else if (0 == (exit_code <- .standalone_types_check_dot_call(
+    ffi_standalone_check_number_1.0.7,
+    x,
+    allow_decimal = TRUE,
+    min,
+    max,
+    allow_infinite,
+    allow_na,
+    allow_null
+  ))) {
+    return(invisible(NULL))
+  }
+
+  .stop_not_number(
+    x,
+    ...,
+    exit_code = exit_code,
+    allow_decimal = TRUE,
+    min = min,
+    max = max,
+    allow_na = allow_na,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_number_whole <- function(x,
+                               ...,
+                               min = NULL,
+                               max = NULL,
+                               allow_infinite = FALSE,
+                               allow_na = FALSE,
+                               allow_null = FALSE,
+                               arg = caller_arg(x),
+                               call = caller_env()) {
+  if (missing(x)) {
+    exit_code <- IS_NUMBER_false
+  } else if (0 == (exit_code <- .standalone_types_check_dot_call(
+    ffi_standalone_check_number_1.0.7,
+    x,
+    allow_decimal = FALSE,
+    min,
+    max,
+    allow_infinite,
+    allow_na,
+    allow_null
+  ))) {
+    return(invisible(NULL))
+  }
+
+  .stop_not_number(
+    x,
+    ...,
+    exit_code = exit_code,
+    allow_decimal = FALSE,
+    min = min,
+    max = max,
+    allow_na = allow_na,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+.stop_not_number <- function(x,
+                             ...,
+                             exit_code,
+                             allow_decimal,
+                             min,
+                             max,
+                             allow_na,
+                             allow_null,
+                             arg,
+                             call) {
+  if (allow_decimal) {
+    what <- "a number"
+  } else {
+    what <- "a whole number"
+  }
+
+  if (exit_code == IS_NUMBER_oob) {
+    min <- min %||% -Inf
+    max <- max %||% Inf
+
+    if (min > -Inf && max < Inf) {
+      what <- sprintf("%s between %s and %s", what, min, max)
+    } else if (x < min) {
+      what <- sprintf("%s larger than or equal to %s", what, min)
+    } else if (x > max) {
+      what <- sprintf("%s smaller than or equal to %s", what, max)
+    } else {
+      abort("Unexpected state in OOB check", .internal = TRUE)
+    }
+  }
+
+  stop_input_type(
+    x,
+    what,
+    ...,
+    allow_na = allow_na,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_symbol <- function(x,
+                         ...,
+                         allow_null = FALSE,
+                         arg = caller_arg(x),
+                         call = caller_env()) {
+  if (!missing(x)) {
+    if (is_symbol(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a symbol",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_arg <- function(x,
+                      ...,
+                      allow_null = FALSE,
+                      arg = caller_arg(x),
+                      call = caller_env()) {
+  if (!missing(x)) {
+    if (is_symbol(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "an argument name",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_call <- function(x,
+                       ...,
+                       allow_null = FALSE,
+                       arg = caller_arg(x),
+                       call = caller_env()) {
+  if (!missing(x)) {
+    if (is_call(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a defused call",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_environment <- function(x,
+                              ...,
+                              allow_null = FALSE,
+                              arg = caller_arg(x),
+                              call = caller_env()) {
+  if (!missing(x)) {
+    if (is_environment(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "an environment",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_function <- function(x,
+                           ...,
+                           allow_null = FALSE,
+                           arg = caller_arg(x),
+                           call = caller_env()) {
+  if (!missing(x)) {
+    if (is_function(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a function",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_closure <- function(x,
+                          ...,
+                          allow_null = FALSE,
+                          arg = caller_arg(x),
+                          call = caller_env()) {
+  if (!missing(x)) {
+    if (is_closure(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "an R function",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_formula <- function(x,
+                          ...,
+                          allow_null = FALSE,
+                          arg = caller_arg(x),
+                          call = caller_env()) {
+  if (!missing(x)) {
+    if (is_formula(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a formula",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+
+# Vectors -----------------------------------------------------------------
+
+# TODO: Figure out what to do with logical `NA` and `allow_na = TRUE`
+
+check_character <- function(x,
+                            ...,
+                            allow_na = TRUE,
+                            allow_null = FALSE,
+                            arg = caller_arg(x),
+                            call = caller_env()) {
+
+  if (!missing(x)) {
+    if (is_character(x)) {
+      if (!allow_na && any(is.na(x))) {
+        abort(
+          sprintf("`%s` can't contain NA values.", arg),
+          arg = arg,
+          call = call
+        )
+      }
+
+      return(invisible(NULL))
+    }
+
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a character vector",
+    ...,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_logical <- function(x,
+                          ...,
+                          allow_null = FALSE,
+                          arg = caller_arg(x),
+                          call = caller_env()) {
+  if (!missing(x)) {
+    if (is_logical(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a logical vector",
+    ...,
+    allow_na = FALSE,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+check_data_frame <- function(x,
+                             ...,
+                             allow_null = FALSE,
+                             arg = caller_arg(x),
+                             call = caller_env()) {
+  if (!missing(x)) {
+    if (is.data.frame(x)) {
+      return(invisible(NULL))
+    }
+    if (allow_null && is_null(x)) {
+      return(invisible(NULL))
+    }
+  }
+
+  stop_input_type(
+    x,
+    "a data frame",
+    ...,
+    allow_null = allow_null,
+    arg = arg,
+    call = call
+  )
+}
+
+# nocov end