diff --git a/DESCRIPTION b/DESCRIPTION
index 37f0f627..b1e8d294 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -26,7 +26,6 @@ Description: High level functions for parallel programming with 'Rcpp'.
 Depends: R (>= 3.6.0)
 Suggests:
     Rcpp,
-    RUnit,
     knitr,
     rmarkdown
 Roxygen: list(markdown = TRUE)
diff --git a/R/test.R b/R/test.R
new file mode 100644
index 00000000..56446a0a
--- /dev/null
+++ b/R/test.R
@@ -0,0 +1,71 @@
+# Minimal test helpers used by the package's own test scripts in tests/.
+#
+# The test files (tests/test-*.R) are plain R scripts run by 'R CMD check'.
+# Each one begins with a call to test_init(), which performs the shared setup
+# those scripts rely on: choosing a default parallel backend, seeding the RNG
+# for reproducibility, and working around environment quirks that would
+# otherwise break R sub-processes spawned during testing.
+
+# Copy every object in the RcppParallel namespace -- including internal,
+# non-exported functions and constants -- into 'envir', so test scripts can
+# reference them directly without the 'RcppParallel:::' prefix. Modelled on
+# renv:::summon(). test_init() calls this for the test script's environment.
+summon <- function(envir = parent.frame()) {
+   namespace <- asNamespace("RcppParallel")
+   contents <- as.list.environment(namespace, all.names = TRUE)
+   list2env(contents, envir = envir)
+   invisible(envir)
+}
+
+# Assert that 'cond' is true. Like a single-condition stopifnot(), but it also
+# understands the all.equal() idiom: all.equal() returns TRUE when its
+# arguments match and a character description of the differences when they do
+# not, so a character result is reported as a failure. A logical 'cond' passes
+# only if every element is TRUE (NAs count as failures), which makes it safe to
+# pass a logical vector directly, e.g. assert(x > 0).
+assert <- function(cond) {
+
+   label <- paste(deparse(substitute(cond)), collapse = " ")
+
+   # a character result (e.g. from all.equal()) describes a mismatch
+   if (is.character(cond))
+      stop(sprintf("assertion failed: %s\n%s", label, paste(cond, collapse = "\n")),
+           call. = FALSE)
+
+   if (!is.logical(cond) || anyNA(cond) || !all(cond))
+      stop(sprintf("assertion failed: %s", label), call. = FALSE)
+
+   invisible(TRUE)
+
+}
+
+test_init <- function() {
+
+   # R CMD check sets R_TESTS=startup.Rs, which breaks R sub-processes run
+   # with a different working directory (e.g. the Rscript invocations in a
+   # test package's Makevars). Clearing it avoids those failures.
+   # (based on practice in Rcpp)
+   Sys.setenv(R_TESTS = "")
+
+   # make tests that use random data deterministic
+   set.seed(42L)
+
+   # choose a default backend unless one was requested explicitly; tinythread
+   # is always available, so tests can run even where TBB is not enabled
+   backend <- Sys.getenv("RCPP_PARALLEL_BACKEND", unset = NA)
+   if (is.na(backend))
+      Sys.setenv(RCPP_PARALLEL_BACKEND = "tinythread")
+
+   writeLines(paste("Using backend:", Sys.getenv("RCPP_PARALLEL_BACKEND")))
+
+   # ensure the packages used by the C++ tests are available
+   requireNamespace("Rcpp", quietly = TRUE)
+   requireNamespace("RcppParallel", quietly = TRUE)
+
+   # make all RcppParallel functions (including internal ones) directly
+   # referenceable in the calling test script, without the ':::' prefix
+   summon(parent.frame())
+
+   invisible(TRUE)
+
+}
diff --git a/inst/tests/runit.distance.R b/inst/tests/runit.distance.R
deleted file mode 100644
index f85a5802..00000000
--- a/inst/tests/runit.distance.R
+++ /dev/null
@@ -1,18 +0,0 @@
-
-library(Rcpp)
-library(RUnit)
-
-sourceCpp(system.file("tests/cpp/distance.cpp", package = "RcppParallel")) 
-
-test.distance <- function() {
-   
-   n <- 1000
-   m <- matrix(runif(n*10), ncol = 10)
-   m <- m/rowSums(m)
-   
-   checkEquals(
-      rcpp_js_distance(m), 
-      rcpp_parallel_js_distance(m)
-   )
-   
-}
diff --git a/inst/tests/runit.innerproduct.R b/inst/tests/runit.innerproduct.R
deleted file mode 100644
index 2f9260cb..00000000
--- a/inst/tests/runit.innerproduct.R
+++ /dev/null
@@ -1,17 +0,0 @@
-
-library(Rcpp)
-library(RUnit)
-
-sourceCpp(system.file("tests/cpp/innerproduct.cpp", package = "RcppParallel"))
-
-test.innerproduct <- function() {
-   
-   x <- runif(1000000)
-   y <- runif(1000000)
-   
-   checkEquals(
-      innerProduct(x, y), 
-      parallelInnerProduct(x, y)
-   )
-   
-}
diff --git a/inst/tests/runit.sum.R b/inst/tests/runit.sum.R
deleted file mode 100644
index 4792b1cd..00000000
--- a/inst/tests/runit.sum.R
+++ /dev/null
@@ -1,15 +0,0 @@
-
-library(Rcpp)
-library(RUnit)
-
-sourceCpp(system.file("tests/cpp/sum.cpp", package = "RcppParallel"))
-
-test.sum <- function() {
-   
-   v <- as.numeric(c(1:10000000))
-   
-   checkEquals(
-      vectorSum(v), 
-      parallelVectorSum(v)
-   )
-}
diff --git a/inst/tests/runit.transform.R b/inst/tests/runit.transform.R
deleted file mode 100644
index d056dbdb..00000000
--- a/inst/tests/runit.transform.R
+++ /dev/null
@@ -1,15 +0,0 @@
-
-library(Rcpp)
-library(RUnit)
-
-sourceCpp(system.file("tests/cpp/transform.cpp", package = "RcppParallel"))
-
-test.transform <- function() {
-   
-   m <- matrix(as.numeric(c(1:1000000)), nrow = 1000, ncol = 1000)
-   
-   checkEquals(
-      matrixSqrt(m), 
-      parallelMatrixSqrt(m)
-   )   
-}
diff --git a/inst/tests/runit.truefalse_macros.R b/inst/tests/runit.truefalse_macros.R
deleted file mode 100644
index 8e403e36..00000000
--- a/inst/tests/runit.truefalse_macros.R
+++ /dev/null
@@ -1,6 +0,0 @@
-
-library(Rcpp)
-library(RUnit)
-
-sourceCpp(system.file("tests/cpp/truefalse_macros.cpp", package = "RcppParallel"))
-
diff --git a/tests/doRUnit.R b/tests/doRUnit.R
deleted file mode 100644
index 34d49eb7..00000000
--- a/tests/doRUnit.R
+++ /dev/null
@@ -1,41 +0,0 @@
-stopifnot(require(RUnit, quietly = TRUE))
-stopifnot(require(Rcpp, quietly = TRUE))
-stopifnot(require(RcppParallel, quietly = TRUE))
-
-## Set a seed to make the test deterministic
-set.seed(42)
-
-## Set a default backend
-backend <- Sys.getenv("RCPP_PARALLEL_BACKEND", unset = NA)
-if (is.na(backend))
-   Sys.setenv(RCPP_PARALLEL_BACKEND = "tinythread")
-
-writeLines(paste("Using backend:", Sys.getenv("RCPP_PARALLEL_BACKEND")))
-
-## Define tests
-suite <- defineTestSuite(
-   name = "RcppParallel Unit Tests",
-   dirs = system.file("tests", package = "RcppParallel")
-)
-
-## Based on practice in Rcpp to avoid some test failures
-Sys.setenv("R_TESTS" = "")
-
-## Run tests
-tests <- runTestSuite(suite)
-
-## Print results
-printTextProtocol(tests)
-
-## Return success or failure to R CMD CHECK
-if (getErrors(tests)$nFail > 0) {
-   stop("TEST FAILED!")
-}
-
-if (getErrors(tests)$nErr > 0) {
-   stop("TEST HAD ERRORS!")
-}
-
-if (getErrors(tests)$nTestFunc < 1) {
-   stop("NO TEST FUNCTIONS RUN!")
-}
diff --git a/tests/test-distance.R b/tests/test-distance.R
new file mode 100644
index 00000000..7e66bed5
--- /dev/null
+++ b/tests/test-distance.R
@@ -0,0 +1,12 @@
+RcppParallel:::test_init()
+
+Rcpp::sourceCpp(system.file("tests/cpp/distance.cpp", package = "RcppParallel"))
+
+n <- 1000
+m <- matrix(runif(n * 10), ncol = 10)
+m <- m / rowSums(m)
+
+assert(all.equal(
+   rcpp_js_distance(m),
+   rcpp_parallel_js_distance(m)
+))
diff --git a/tests/test-innerproduct.R b/tests/test-innerproduct.R
new file mode 100644
index 00000000..c1374fb0
--- /dev/null
+++ b/tests/test-innerproduct.R
@@ -0,0 +1,11 @@
+RcppParallel:::test_init()
+
+Rcpp::sourceCpp(system.file("tests/cpp/innerproduct.cpp", package = "RcppParallel"))
+
+x <- runif(1000000)
+y <- runif(1000000)
+
+assert(all.equal(
+   innerProduct(x, y),
+   parallelInnerProduct(x, y)
+))
diff --git a/tests/testInstallLibs.R b/tests/test-install-libs.R
similarity index 99%
rename from tests/testInstallLibs.R
rename to tests/test-install-libs.R
index 387381b1..3b98806b 100644
--- a/tests/testInstallLibs.R
+++ b/tests/test-install-libs.R
@@ -6,6 +6,8 @@
 # helper definitions that precede its '# Main' section (evaluating the whole
 # file would trigger an actual install), and exercise them directly.
 
+RcppParallel:::test_init()
+
 # locate src/install.libs.R by walking up from the working directory; this is
 # reachable when tests are run from the package sources. If it cannot be found
 # (e.g. only the installed package is available), skip rather than fail.
diff --git a/tests/scalable-allocator.R b/tests/test-scalable-allocator.R
similarity index 92%
rename from tests/scalable-allocator.R
rename to tests/test-scalable-allocator.R
index c2944193..0957178c 100644
--- a/tests/scalable-allocator.R
+++ b/tests/test-scalable-allocator.R
@@ -9,7 +9,7 @@
 #
 # https://github.com/RcppCore/RcppParallel/pull/262
 
-library(RcppParallel)
+RcppParallel:::test_init()
 
 # building the test package requires a toolchain, so keep this test
 # off of CRAN's machines
@@ -20,7 +20,7 @@ if (!ci) {
 }
 
 # the scalable allocator is only available with the TBB backend
-if (!RcppParallel:::TBB_ENABLED) {
+if (!TBB_ENABLED) {
    writeLines("TBB is not enabled; skipping scalable allocator test.")
    quit(save = "no")
 }
@@ -89,11 +89,6 @@ libDir <- file.path(tempdir(), "library")
 dir.create(libDir, recursive = TRUE, showWarnings = FALSE)
 Sys.setenv(R_LIBS = paste(.libPaths(), collapse = .Platform$path.sep))
 
-# R CMD check sets R_TESTS=startup.Rs, which breaks R sub-processes run
-# with a different working directory -- like the Rscript invocations in
-# the test package's Makevars (see also tests/doRUnit.R)
-Sys.setenv(R_TESTS = "")
-
 rExe <- file.path(R.home("bin"), if (.Platform$OS.type == "windows") "R.exe" else "R")
 args <- c("CMD", "INSTALL", "--no-multiarch", paste0("--library=", shQuote(libDir)), shQuote(pkgRoot))
 
@@ -108,4 +103,4 @@ if (is.numeric(status) && status != 0L)
 invisible(loadNamespace("scalabletest", lib.loc = libDir))
 ok <- .Call("scalable_roundtrip", 1000L, PACKAGE = "scalabletest")
 writeLines(paste("scalable allocator round trip:", if (isTRUE(ok)) "OK" else "FAILED"))
-stopifnot(isTRUE(ok))
+assert(isTRUE(ok))
diff --git a/tests/test-sum.R b/tests/test-sum.R
new file mode 100644
index 00000000..3133d05a
--- /dev/null
+++ b/tests/test-sum.R
@@ -0,0 +1,10 @@
+RcppParallel:::test_init()
+
+Rcpp::sourceCpp(system.file("tests/cpp/sum.cpp", package = "RcppParallel"))
+
+v <- as.numeric(1:10000000)
+
+assert(all.equal(
+   vectorSum(v),
+   parallelVectorSum(v)
+))
diff --git a/tests/test-transform.R b/tests/test-transform.R
new file mode 100644
index 00000000..25edc985
--- /dev/null
+++ b/tests/test-transform.R
@@ -0,0 +1,10 @@
+RcppParallel:::test_init()
+
+Rcpp::sourceCpp(system.file("tests/cpp/transform.cpp", package = "RcppParallel"))
+
+m <- matrix(as.numeric(1:1000000), nrow = 1000, ncol = 1000)
+
+assert(all.equal(
+   matrixSqrt(m),
+   parallelMatrixSqrt(m)
+))
diff --git a/tests/test-truefalse-macros.R b/tests/test-truefalse-macros.R
new file mode 100644
index 00000000..3259d7a8
--- /dev/null
+++ b/tests/test-truefalse-macros.R
@@ -0,0 +1,5 @@
+RcppParallel:::test_init()
+
+# this file has no runtime assertions: the TRUE/FALSE macro checks are
+# static_assert()s in the C++ source, so a successful compile is the test
+Rcpp::sourceCpp(system.file("tests/cpp/truefalse_macros.cpp", package = "RcppParallel"))