diff --git a/src/RoundingIntegers.jl b/src/RoundingIntegers.jl
index 35f1101..148d6b6 100644
--- a/src/RoundingIntegers.jl
+++ b/src/RoundingIntegers.jl
@@ -135,6 +135,7 @@ Base.flipsign(x::RSigned, y::RSigned) = RInteger(flipsign(Integer(x), Integer(y)
 Base.count_ones(x::RInteger) = count_ones(Integer(x))
 Base.leading_zeros(x::RInteger) = leading_zeros(Integer(x))
 Base.trailing_zeros(x::RInteger) = trailing_zeros(Integer(x))
+Base.ndigits0z(x::RInteger) = Base.ndigits0z(Integer(x))
 
 # A few operations preserve the type
 -(x::RInteger) = RInteger(-Integer(x))
diff --git a/test/runtests.jl b/test/runtests.jl
index 70e4de0..f995616 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -61,6 +61,8 @@ end
     @test copysign(r, r) === r
     @test unsigned(r) === RUInt(5)
     @test hex(r) == "5"
+
+    @test string(RInt(7.2)) == "7"
 end
 
 @testset "Rounding" begin