diff --git a/base/random.jl b/base/random.jl
index 1267f58d53717..b8e8c90d0a220 100644
--- a/base/random.jl
+++ b/base/random.jl
@@ -126,7 +126,7 @@ end
 @inline rand_ui2x52_raw(r::MersenneTwister) = rand_ui52_raw(r) % UInt128 << 64 | rand_ui52_raw(r)
 
 function srand(r::MersenneTwister, seed::Vector{UInt32})
-    r.seed = seed
+    copy!(resize!(r.seed, length(seed)), seed)
     dsfmt_init_by_array(r.state, r.seed)
     mt_setempty!(r)
     return r
diff --git a/test/random.jl b/test/random.jl
index 9b0a601a9aafc..1e824f98e9905 100644
--- a/test/random.jl
+++ b/test/random.jl
@@ -430,9 +430,17 @@ let seed = rand(UInt32, 10)
     @test s == r
 end
 
-# intialization
+# MersenneTwister initialization with invalid values
 @test_throws DomainError Base.dSFMT.DSFMT_state(zeros(Int32, rand(0:Base.dSFMT.JN32-1)))
 @test_throws DomainError MersenneTwister(zeros(UInt32, 1), Base.dSFMT.DSFMT_state(),
                                          zeros(Float64, 10), 0)
 @test_throws DomainError MersenneTwister(zeros(UInt32, 1), Base.dSFMT.DSFMT_state(),
                                          zeros(Float64, Base.Random.MTCacheLength), -1)
+
+# seed is private to MersenneTwister
+let seed = rand(UInt32, 10)
+    r = MersenneTwister(seed)
+    @test r.seed == seed && r.seed !== seed
+    resize!(seed, 4)
+    @test r.seed != seed
+end