diff --git a/test/testutils.jl b/test/testutils.jl
index ac0400d..840ec78 100644
--- a/test/testutils.jl
+++ b/test/testutils.jl
@@ -236,8 +236,8 @@ function pdtest_mul(C, Cmat::Matrix, X::Matrix, verbose::Int)
     end
 
     # Dimension mismatches
-    @test_throws DimensionMismatch C * rand(d + 1)
-    @test_throws DimensionMismatch C * rand(d + 1, n)
+    @test_throws DimensionMismatch C * rand(d + 2)
+    @test_throws DimensionMismatch C * rand(d + 2, n)
 end