diff --git a/stdlib/Printf/src/Printf.jl b/stdlib/Printf/src/Printf.jl
index ac57f95ec6bb9..e00b6becbb0f1 100644
--- a/stdlib/Printf/src/Printf.jl
+++ b/stdlib/Printf/src/Printf.jl
@@ -547,7 +547,7 @@ const __BIG_FLOAT_MAX__ = 8192
 end
 
 # pointers
-fmt(buf, pos, arg, spec::Spec{Pointer}) = fmt(buf, pos, Int(arg), ptrfmt(spec, arg))
+fmt(buf, pos, arg, spec::Spec{Pointer}) = fmt(buf, pos, UInt64(arg), ptrfmt(spec, arg))
 
 # old Printf compat
 function fix_dec end
diff --git a/stdlib/Printf/test/runtests.jl b/stdlib/Printf/test/runtests.jl
index c74739d66ba51..f6645464b4797 100644
--- a/stdlib/Printf/test/runtests.jl
+++ b/stdlib/Printf/test/runtests.jl
@@ -19,6 +19,9 @@ using Test, Printf
         @test (@sprintf "%-20p" C_NULL) == "0x00000000          "
     end
 
+    #40318
+    @test @sprintf("%p", 0xfffffffffffe0000) == "0xfffffffffffe0000"
+
 end
 
 @testset "%a" begin