diff --git a/test/runtests.jl b/test/runtests.jl
index 1aa8bb635b..d5561bb929 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -1,10 +1,14 @@
 include("test_utils/SelectiveTests.jl")
 using .SelectiveTests: isincluded, parse_args
 using Pkg
+using Random: seed!
 using Test
 using TimerOutputs: TimerOutputs, @timeit
 import Turing
 
+# Fix the global Random.seed for reproducibility.
+seed!(23)
+
 include(pkgdir(Turing) * "/test/test_utils/models.jl")
 include(pkgdir(Turing) * "/test/test_utils/numerical_tests.jl")
 include(pkgdir(Turing) * "/test/test_utils/ad_utils.jl")