diff --git a/base/src/test/mod.rs b/base/src/test/mod.rs
index 9f67c79..f53465d 100644
--- a/base/src/test/mod.rs
+++ b/base/src/test/mod.rs
@@ -46,6 +46,7 @@ pub(crate) mod util;
 
 mod engineering;
 mod test_fn_offset;
+mod test_fn_or;
 mod test_number_format;
 
 mod test_escape_quotes;
diff --git a/base/src/test/test_fn_or.rs b/base/src/test/test_fn_or.rs
new file mode 100644
index 0000000..3c49b8a
--- /dev/null
+++ b/base/src/test/test_fn_or.rs
@@ -0,0 +1,36 @@
+#![allow(clippy::unwrap_used)]
+
+use crate::test::util::new_empty_model;
+
+#[test]
+fn fn_or() {
+    let mut model = new_empty_model();
+    model._set("A1", "=OR(1, 0)");
+    model._set("A2", "=OR(0, 0)");
+    model._set("A3", "=OR(true, false)");
+    model._set("A4", "=OR(false, false)");
+
+    model.evaluate();
+    assert_eq!(model._get_text("A1"), *"TRUE");
+    assert_eq!(model._get_text("A2"), *"FALSE");
+    assert_eq!(model._get_text("A3"), *"TRUE");
+    assert_eq!(model._get_text("A4"), *"FALSE");
+}
+
+#[test]
+fn fn_or_no_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=OR()");
+    model.evaluate();
+    assert_eq!(model._get_text("A1"), *"#ERROR!");
+}
+
+#[test]
+fn fn_or_missing_arguments() {
+    let mut model = new_empty_model();
+    model._set("A1", "=OR(,)");
+    model._set("A2", "=OR(,1)");
+    model.evaluate();
+    assert_eq!(model._get_text("A1"), *"FALSE");
+    assert_eq!(model._get_text("A2"), *"TRUE");
+}