diff --git a/tests/testthat/test-estparnormratio.R b/tests/testthat/test-estparnormratio.R
new file mode 100644
index 0000000000000000000000000000000000000000..517c67c20e2ba60f473b99049a4860d240009cd4
--- /dev/null
+++ b/tests/testthat/test-estparnormratio.R
@@ -0,0 +1,35 @@
+set.seed(1234)
+x1 <- rnorm(2048, 1, 5)
+y1 <- rnorm(2048, 10, 10)
+z1 <- x1/y1
+beta1 <- 0.1; rho1 <- 2; delta1 <- 1
+theta1 <- estparnormratio(z1, eps = 1e-6)
+test_that("estparnormratio works 1", {
+  expect_equal(round(theta1$beta, 1), beta1)
+  expect_equal(round(theta1$rho, 0), rho1)
+  expect_equal(round(theta1$delta, 1), delta1)
+})
+
+set.seed(1234)
+x2 <- rnorm(2048, 0, 5)
+y2 <- rnorm(2048, 10, 10)
+z2 <- x2/y2
+beta2 <- 0; rho2 <- 2; delta2 <- 1
+theta2 <- estparnormratio(z2, eps = 1e-6)
+test_that("estparnormratio works 2", {
+  expect_equal(round(theta2$beta, 1), beta2)
+  expect_equal(round(theta2$rho, 1), rho2)
+  expect_equal(round(theta2$delta, 1), delta2)
+})
+
+set.seed(1234)
+x3 <- rnorm(2048, -1.5*20, 20/3)
+y3 <- rnorm(2048, 20, 20/3*1.5)
+z3 <- x3/y3
+beta3 <- -1.5; rho3 <- 1.5; delta3 <- 0.5
+theta3 <- estparnormratio(z3, eps = 1e-6)
+test_that("estparnormratio works 3", {
+  expect_equal(round(theta3$beta, 1), beta3)
+  expect_equal(round(theta3$rho, 1), rho3)
+  expect_equal(round(abs(theta3$delta), 2), delta3)
+})