diff --git a/DESCRIPTION b/DESCRIPTION
index 09883c6..4da723c 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -11,6 +11,7 @@ Description: Contains a number of common astronomy utility functions for cosmolo
 License: LGPL-3
 LazyData: TRUE
 Depends: R (>= 3.00), RANN, NISTunits, pracma
-Suggests: plotrix, igraph
+Suggests: plotrix, igraph, testthat (>= 3.0.0)
 LinkingTo: Rcpp
 NeedsCompilation: yes
+Config/testthat/edition: 3
diff --git a/tests/testthat.R b/tests/testthat.R
new file mode 100644
index 0000000..520be89
--- /dev/null
+++ b/tests/testthat.R
@@ -0,0 +1,4 @@
+library(testthat)
+library(celestial)
+
+test_check("celestial")
diff --git a/tests/testthat/test-coordinate-matching.R b/tests/testthat/test-coordinate-matching.R
new file mode 100644
index 0000000..ed94bcb
--- /dev/null
+++ b/tests/testthat/test-coordinate-matching.R
@@ -0,0 +1,11 @@
+test_that("single-coordinate matching chooses the nearest in-radius source", {
+  matches <- coordmatchsing(
+    RAref = 0, Decref = 0,
+    coordcompare = rbind(c(1, 0), c(0, 0)),
+    rad = 2, radunit = "deg"
+  )
+
+  expect_equal(matches$ID, c(2, 1))
+  expect_equal(unname(matches$bestmatch["compareID"]), 2)
+  expect_equal(unname(matches$bestmatch["sep"]), 0, tolerance = 1e-10)
+})