diff --git a/base/gmp.jl b/base/gmp.jl
index 08421383a28fb..dea7da7edd108 100644
--- a/base/gmp.jl
+++ b/base/gmp.jl
@@ -288,6 +288,7 @@ function BigInt(x::Integer)
     z = MPZ.realloc2(nd)
     s = sign(x)
     s == -1 && (x = -x)
+    x = unsigned(x)
     size = 0
     limbnbits = sizeof(Limb) << 3
     while nd > 0
diff --git a/test/bigint.jl b/test/bigint.jl
index 6273c96674d42..e2427dea09738 100644
--- a/test/bigint.jl
+++ b/test/bigint.jl
@@ -432,3 +432,11 @@ end
     y = rand(UInt128)
     @test BigInt(y) % UInt128 === y
 end
+
+@testset "conversion from typemin(T)" begin
+    @test big(Int8(-128)) == big"-128"
+    @test big(Int16(-32768)) == big"-32768"
+    @test big(Int32(-2147483648)) == big"-2147483648"
+    @test big(Int64(-9223372036854775808)) == big"-9223372036854775808"
+    @test big(Int128(-170141183460469231731687303715884105728)) == big"-170141183460469231731687303715884105728"
+end