diff --git a/R/generic_metric_coerce.R b/R/generic_metric_coerce.R
index eb5317e..3df6751 100644
--- a/R/generic_metric_coerce.R
+++ b/R/generic_metric_coerce.R
@@ -41,3 +41,36 @@ method(
   function(from, to, ...) {
     as.integer(from, ...)
   }
+
+method(
+  metric_coerce,
+  list(
+    new_union(class_character, class_integer, class_logical),
+    new_S3_class(class_desc(class_double))
+  )
+) <-
+  function(from, to, ...) {
+    as.double(from, ...)
+  }
+
+method(
+  metric_coerce,
+  list(
+    new_union(class_character, class_double, class_integer),
+    new_S3_class(class_desc(class_logical))
+  )
+) <-
+  function(from, to, ...) {
+    as.logical(from, ...)
+  }
+
+method(
+  metric_coerce,
+  list(
+    new_union(class_double, class_integer, class_logical),
+    new_S3_class(class_desc(class_character))
+  )
+) <-
+  function(from, to, ...) {
+    as.character(from, ...)
+  }
diff --git a/tests/testthat/test-metric_coerce.R b/tests/testthat/test-metric_coerce.R
new file mode 100644
index 0000000..e246ead
--- /dev/null
+++ b/tests/testthat/test-metric_coerce.R
@@ -0,0 +1,66 @@
+test_that("metric_coerce coerces character metrics to each atomic type", {
+  ms <- metrics()
+
+  # integer metric
+  expect_identical(
+    metric_coerce("3", ms[["r_cmd_check_error_count"]]@data_class),
+    3L
+  )
+
+  # logical metric
+  expect_identical(
+    metric_coerce("TRUE", ms[["has_website"]]@data_class),
+    TRUE
+  )
+  expect_identical(
+    metric_coerce("FALSE", ms[["has_website"]]@data_class),
+    FALSE
+  )
+
+  # double metric
+  expect_identical(
+    metric_coerce("0.5", ms[["test_line_coverage_fraction"]]@data_class),
+    0.5
+  )
+})
+
+test_that("metric_coerce coerces atomic values to character", {
+  expect_identical(metric_coerce(3L, class_character), "3")
+  expect_identical(metric_coerce(0.5, class_character), "0.5")
+  expect_identical(metric_coerce(TRUE, class_character), "TRUE")
+})
+
+test_that("convert package_matrix to metric_data_frame handles atomic types", {
+  set.seed(1)
+  repo <- suppressWarnings(random_repo(n = 4))
+  on.exit(unlink(sub("^file://", "", repo), recursive = TRUE))
+
+  # metric fields are non-standard, so discover them from the PACKAGES DCF
+  packages_url <- file.path(
+    sub("^file://", "", repo),
+    "src", "contrib", "PACKAGES"
+  )
+  dcf <- paste(readLines(packages_url), collapse = "\n")
+  metric_fields <- grep(
+    "^Metric/",
+    colnames(read.dcf(textConnection(dcf))),
+    value = TRUE
+  )
+
+  db <- available.packages(
+    repos = repo,
+    fields = metric_fields,
+    filters = list()
+  )
+  db <- db[!is.na(db[, "Package"]), , drop = FALSE]
+
+  expect_no_error(
+    met <- convert(class_package_matrix(db), class_metric_data_frame)
+  )
+
+  # logical, double and integer metrics should have been coerced away from
+  # their character storage representation
+  expect_type(met[["has_website"]], "logical")
+  expect_type(met[["test_line_coverage_fraction"]], "double")
+  expect_type(met[["r_cmd_check_error_count"]], "integer")
+})