diff --git a/.gitignore b/.gitignore
index fb33997b7..cab23c2e9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,6 +2,8 @@
 .Rproj.user
 /.Rhistory
 
+tests/testthat/testthat-problems.rds
+
 ## Qt Creator
 *.pro
 *.pro.user
diff --git a/NEWS.md b/NEWS.md
index fb8da8949..5cc17bd51 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,6 +1,7 @@
 # roxygen2 (development version)
 
 * `@family` lists are now ordered more carefully, "foo1" comes after "foo" (#1563, @krlmlr).
+* Re-runs of `namespace_roclet()` fixed for packages using multi-line `@rawNamespace` directives (#1572, @MichaelChirico).
 
 # roxygen2 7.3.0
 
diff --git a/R/namespace.R b/R/namespace.R
index d33e56b05..1a1b1e0fa 100644
--- a/R/namespace.R
+++ b/R/namespace.R
@@ -74,7 +74,7 @@ update_namespace_imports <- function(base_path) {
   }
 
   lines <- c(namespace_imports(base_path), namespace_exports(NAMESPACE))
-  results <- c(made_by("#"), sort_c(unique(lines)))
+  results <- c(made_by("#"), sort_c(unique(trimws(lines))))
   write_if_different(NAMESPACE, results, check = TRUE)
 
   invisible()
@@ -109,12 +109,15 @@ namespace_imports_blocks <- function(srcref) {
   }))
 }
 
+# NB: this is designed as the conjugate of namespace_imports(), so also
+#   includes @rawNamespace entries which may/may not also include import directives.
 namespace_exports <- function(path) {
   parsed <- as.list(parse(path, keep.source = TRUE))
 
   is_import_directive <- function(x) is_call(x, import_directives)
   export_lines <- attr(parsed, "srcref")[!map_lgl(parsed, is_import_directive)]
-  unlist(lapply(export_lines, as.character))
+  # Each multiline directives are a single element so they're sorted correctly
+  unlist(lapply(export_lines, function(x) paste(as.character(x), collapse = "\n")))
 }
 
 # NAMESPACE generation ----------------------------------------------------
diff --git a/tests/testthat/test-namespace.R b/tests/testthat/test-namespace.R
index c6322cdec..d5c30ba47 100644
--- a/tests/testthat/test-namespace.R
+++ b/tests/testthat/test-namespace.R
@@ -305,6 +305,17 @@ test_that("rawNamespace inserted unchanged", {
   expect_equal(out, "xyz\n  abc")
 })
 
+test_that("rawNamespace does not break idempotency", {
+  test_pkg <- test_path("testRawNamespace")
+  NAMESPACE <- file.path(test_pkg, "NAMESPACE")
+
+  lines_orig <- read_lines(NAMESPACE)
+
+  expect_no_error(roxygenize(test_pkg, namespace_roclet()))
+
+  # contents unchanged
+  expect_equal(read_lines(NAMESPACE), lines_orig)
+})
 
 # @evalNamespace ----------------------------------------------------------
 
@@ -391,7 +402,13 @@ test_that("can extract non-imports from namespace preserving source", {
     "export(b)"
   )
   path <- withr::local_tempfile(lines = lines)
-  expect_equal(namespace_exports(path), lines[c(1:3, 5)])
+  expect_equal(
+    namespace_exports(path),
+    c(
+      paste(lines[1:3], collapse = "\n"),
+      lines[5L]
+    )
+  )
 })
 
 test_that("Invalid imports throw a helpful error", {
diff --git a/tests/testthat/testRawNamespace/DESCRIPTION b/tests/testthat/testRawNamespace/DESCRIPTION
new file mode 100644
index 000000000..633c5420f
--- /dev/null
+++ b/tests/testthat/testRawNamespace/DESCRIPTION
@@ -0,0 +1,9 @@
+Package: testRawNamespace
+Title: Check that re-running on multi-line @rawNamespace directive is OK
+License: GPL-2
+Description: testRawNamespace.
+Author: Hadley <hadley@rstudio.com>
+Maintainer: Hadley <hadley@rstudio.com>
+Encoding: UTF-8
+Version: 0.1
+RoxygenNote: 7.3.0.9000
diff --git a/tests/testthat/testRawNamespace/NAMESPACE b/tests/testthat/testRawNamespace/NAMESPACE
new file mode 100644
index 000000000..74ea7af2a
--- /dev/null
+++ b/tests/testthat/testRawNamespace/NAMESPACE
@@ -0,0 +1,10 @@
+# Generated by roxygen2: do not edit by hand
+
+
+if (TRUE) {
+  import(grDevices)
+} else {
+  import(methods)
+}
+import(graphics)
+import(utils)
diff --git a/tests/testthat/testRawNamespace/R/a.R b/tests/testthat/testRawNamespace/R/a.R
new file mode 100644
index 000000000..a44b2fe03
--- /dev/null
+++ b/tests/testthat/testRawNamespace/R/a.R
@@ -0,0 +1,9 @@
+#' @import graphics
+#' @rawNamespace
+#' if (TRUE) {
+#'   import(grDevices)
+#' } else {
+#'   import(methods)
+#' }
+#' @import utils
+NULL