diff --git a/base/boot.jl b/base/boot.jl
index d71ecfdedbdf6..80e8ac70d1b56 100644
--- a/base/boot.jl
+++ b/base/boot.jl
@@ -747,7 +747,7 @@ Int64(x::Ptr) = Int64(UInt32(x))
 UInt64(x::Ptr) = UInt64(UInt32(x))
 end
 Ptr{T}(x::Union{Int,UInt,Ptr}) where {T} = bitcast(Ptr{T}, x)
-Ptr{T}() where {T} = Ptr{T}(0)
+Ptr{T}() where {T} = Ptr{T}(C_NULL)
 
 Signed(x::UInt8)    = Int8(x)
 Unsigned(x::Int8)   = UInt8(x)