diff --git a/crates/xenia-cpu/src/overflow.rs b/crates/xenia-cpu/src/overflow.rs
index a55f505..79bba9c 100644
--- a/crates/xenia-cpu/src/overflow.rs
+++ b/crates/xenia-cpu/src/overflow.rs
@@ -162,6 +162,11 @@ mod tests {
     fn mulld_overflows() {
         assert!(mulld_ov(i64::MAX, 2));
         assert!(!mulld_ov(i64::MAX, 1));
+        // PPCBUG-022: INT_MIN * -1 overflows (=-INT_MIN > INT_MAX).
+        // checked_mul correctly returns None for this case.
+        assert!(mulld_ov(i64::MIN, -1), "INT_MIN * -1 overflows i64");
+        assert!(!mulld_ov(i64::MIN, 1));
+        assert!(!mulld_ov(i64::MIN + 1, -1), "INT_MIN+1 * -1 = INT_MAX, no overflow");
     }
 
     #[test]