diff --git a/src/testing.jl b/src/testing.jl
index fc0ac017..083ad7c2 100644
--- a/src/testing.jl
+++ b/src/testing.jl
@@ -109,6 +109,7 @@ function Base.unsafe_read(io::AsyncIO, to::Ptr{UInt8}, nb::UInt)
             splice!(buffer, 1:n)
             written += n
         end
+        istaskdone(io.task) && throw(EOFError())
     end
 end