diff --git a/src/ParallelTestRunner.jl b/src/ParallelTestRunner.jl
index 18d954b..32e8cce 100644
--- a/src/ParallelTestRunner.jl
+++ b/src/ParallelTestRunner.jl
@@ -7,9 +7,6 @@ using Dates
 using Printf: @sprintf
 using Base.Filesystem: path_separator
 using Statistics
-using Scratch
-using Serialization
-using FileWatching: Pidfile
 import Test
 import Random
 import IOCapture
@@ -475,140 +472,8 @@ function default_njobs(;
     return max(1, min(_cpu_threads, memory_jobs))
 end
 
-# Struct used in runtests to sort failed tests before successful ones
-struct TestHistoryEntry
-    duration::Float64
-    failed::Bool
-end
-# successful tests < failed tests, so when reversing the
-# sort they are also in proper descending order
-Base.isless(a::TestHistoryEntry, b::TestHistoryEntry) = a.failed == b.failed ? a.duration < b.duration : a.failed < b.failed
-
-# Historical test duration database
-function get_history_file(mod::Module, history_key::Union{Nothing, AbstractString} = nothing)
-    # History file version. Change when modifying the history format
-    hist_ver = "v2"
-    scratch_dir = @get_scratch!("durations")
-    name = string(nameof(mod))
-    if history_key !== nothing
-        isempty(history_key) && throw(ArgumentError("history_key must not be empty"))
-        name *= "-" * replace(history_key, r"[^\w.-]" => "_")
-    end
-    return joinpath(scratch_dir, "v$(VERSION.major).$(VERSION.minor)", hist_ver, "$name.jls")
-end
-function load_test_history(mod::Module, history_key = nothing)
-    history_file = get_history_file(mod, history_key)
-    if isfile(history_file)
-        try
-            return deserialize(history_file)::Tuple{Dict{String, Float64}, Set{String}}
-        catch e
-            @warn "Failed to load test history from $history_file" exception=e
-        end
-    end
-    return (Dict{String, Float64}(), Set{String}())
-end
-
-# Runs on the same machine share the history file, so all writes happen under a lock and go
-# through a temporary file, which keeps readers from ever seeing a partially written history.
-const history_lock_stale_age = 60
-
-function with_history_lock(f, history_file)
-    mkpath(dirname(history_file))
-    lock_file = history_file * ".lock"
-    # Without waiting, Pidfile removes a lock left behind by a dead process right away; when
-    # waiting, it only checks for staleness after `stale_age` has passed.
-    lock = try
-        Pidfile.mkpidlock(lock_file; stale_age=history_lock_stale_age, wait=false)
-    catch err
-        err isa Pidfile.PidlockedError || rethrow()
-        Pidfile.mkpidlock(lock_file; stale_age=history_lock_stale_age)
-    end
-    try
-        return f()
-    finally
-        close(lock)
-    end
-end
-
-function write_test_history(history_file, history::Tuple{Dict{String, Float64}, Set{String}})
-    temporary_file = history_file * ".tmp.$(getpid())"
-    serialize(temporary_file, history)
-    mv(temporary_file, history_file; force=true)
-    return nothing
-end
-
-"""
-    update_test_history!(mod, durations, passed, failed)
-
-Merge the outcome of the tests this run completed into the on-disk history of `mod`: `durations`
-maps test names to seconds, `passed` and `failed` are the names to remove from and add to the
-set of failing tests. Entries of tests not mentioned are left as they are, so concurrent runs
-on the same machine only ever update their own tests.
-"""
-function update_test_history!(mod::Module, durations::Dict{String, Float64},
-                              passed::Set{String}, failed::Set{String}; history_key = nothing)
-    history_file = get_history_file(mod, history_key)
-    try
-        with_history_lock(history_file) do
-            stored_durations, stored_failures = load_test_history(mod, history_key)
-            merge!(stored_durations, durations)
-            setdiff!(stored_failures, passed)
-            union!(stored_failures, failed)
-            write_test_history(history_file, (stored_durations, stored_failures))
-        end
-    catch e
-        @warn "Failed to update test history in $history_file" exception=e
-    end
-    return nothing
-end
-
-# Outcomes of finished tests waiting to be merged into the history file. Writing them in
-# batches keeps the number of lock, write and rename operations low on slow filesystems, while
-# an interrupted run still keeps all but the last few measurements.
-struct PendingHistory
-    durations::Dict{String, Float64}
-    passed::Set{String}
-    failed::Set{String}
-end
-PendingHistory() = PendingHistory(Dict{String, Float64}(), Set{String}(), Set{String}())
-
-function record_test_history!(pending::Lockable{PendingHistory}, mod::Module, test::String, result, duration::Real;
-                              history_flush_every::Integer, history_key = nothing)
-    failed = !(result isa AbstractTestRecord) || anynonpass(result[])
-    batch = @lock pending begin
-        pending[].durations[test] = Float64(duration)
-        push!(failed ? pending[].failed : pending[].passed, test)
-        length(pending[].durations) >= history_flush_every ? take_pending_history!(pending[]) : nothing
-    end
-    batch === nothing || update_test_history!(mod, batch...; history_key)
-    return nothing
-end
-
-function take_pending_history!(pending::PendingHistory)
-    batch = (copy(pending.durations), copy(pending.passed), copy(pending.failed))
-    empty!(pending.durations); empty!(pending.passed); empty!(pending.failed)
-    return batch
-end
-
-function flush_test_history!(pending::Lockable{PendingHistory}, mod::Module; history_key = nothing)
-    batch = @lock pending take_pending_history!(pending[])
-    isempty(batch[1]) || update_test_history!(mod, batch...; history_key)
-    return nothing
-end
-
-# Replace the whole history, e.g. to seed it in tests.
-function save_test_history(mod::Module, history::Tuple{Dict{String, Float64}, Set{String}};
-                           history_key = nothing)
-    history_file = get_history_file(mod, history_key)
-    try
-        with_history_lock(history_file) do
-            write_test_history(history_file, history)
-        end
-    catch e
-        @warn "Failed to save test history to $history_file" exception=e
-    end
-    return nothing
-end
+include("history.jl")
+using .TestHistory
 
 function test_exe(color::Bool=false)
     test_exeflags = Base.julia_cmd()
diff --git a/src/history.jl b/src/history.jl
new file mode 100644
index 0000000..434a45a
--- /dev/null
+++ b/src/history.jl
@@ -0,0 +1,149 @@
+module TestHistory
+
+using Scratch
+using Serialization
+using FileWatching: Pidfile
+
+import ..ParallelTestRunner as PTR
+
+export TestHistoryEntry, PendingHistory
+export load_test_history, record_test_history!, flush_test_history!, get_history_file, save_test_history, update_test_history!
+
+# Struct used in runtests to sort failed tests before successful ones
+struct TestHistoryEntry
+    duration::Float64
+    failed::Bool
+end
+# successful tests < failed tests, so when reversing the
+# sort they are also in proper descending order
+Base.isless(a::TestHistoryEntry, b::TestHistoryEntry) = a.failed == b.failed ? a.duration < b.duration : a.failed < b.failed
+
+# Historical test duration database
+function get_history_file(mod::Module, history_key::Union{Nothing, AbstractString} = nothing)
+    # History file version. Change when modifying the history format
+    hist_ver = "v2"
+    scratch_dir = @get_scratch!("durations")
+    name = string(nameof(mod))
+    if history_key !== nothing
+        isempty(history_key) && throw(ArgumentError("history_key must not be empty"))
+        name *= "-" * replace(history_key, r"[^\w.-]" => "_")
+    end
+    return joinpath(scratch_dir, "v$(VERSION.major).$(VERSION.minor)", hist_ver, "$name.jls")
+end
+function load_test_history(mod::Module, history_key = nothing)
+    history_file = get_history_file(mod, history_key)
+    if isfile(history_file)
+        try
+            return deserialize(history_file)::Tuple{Dict{String, Float64}, Set{String}}
+        catch e
+            @warn "Failed to load test history from $history_file" exception=e
+        end
+    end
+    return (Dict{String, Float64}(), Set{String}())
+end
+
+# Runs on the same machine share the history file, so all writes happen under a lock and go
+# through a temporary file, which keeps readers from ever seeing a partially written history.
+const history_lock_stale_age = 60
+
+function with_history_lock(f, history_file)
+    mkpath(dirname(history_file))
+    lock_file = history_file * ".lock"
+    # Without waiting, Pidfile removes a lock left behind by a dead process right away; when
+    # waiting, it only checks for staleness after `stale_age` has passed.
+    lock = try
+        Pidfile.mkpidlock(lock_file; stale_age=history_lock_stale_age, wait=false)
+    catch err
+        err isa Pidfile.PidlockedError || rethrow()
+        Pidfile.mkpidlock(lock_file; stale_age=history_lock_stale_age)
+    end
+    try
+        return f()
+    finally
+        close(lock)
+    end
+end
+
+function write_test_history(history_file, history::Tuple{Dict{String, Float64}, Set{String}})
+    temporary_file = history_file * ".tmp.$(getpid())"
+    serialize(temporary_file, history)
+    mv(temporary_file, history_file; force=true)
+    return nothing
+end
+
+"""
+    update_test_history!(mod, durations, passed, failed)
+
+Merge the outcome of the tests this run completed into the on-disk history of `mod`: `durations`
+maps test names to seconds, `passed` and `failed` are the names to remove from and add to the
+set of failing tests. Entries of tests not mentioned are left as they are, so concurrent runs
+on the same machine only ever update their own tests.
+"""
+function update_test_history!(mod::Module, durations::Dict{String, Float64},
+                            passed::Set{String}, failed::Set{String}; history_key = nothing)
+    history_file = get_history_file(mod, history_key)
+    try
+        with_history_lock(history_file) do
+            stored_durations, stored_failures = load_test_history(mod, history_key)
+            merge!(stored_durations, durations)
+            setdiff!(stored_failures, passed)
+            union!(stored_failures, failed)
+            write_test_history(history_file, (stored_durations, stored_failures))
+        end
+    catch e
+        @warn "Failed to update test history in $history_file" exception=e
+    end
+    return nothing
+end
+
+# Outcomes of finished tests waiting to be merged into the history file. Writing them in
+# batches keeps the number of lock, write and rename operations low on slow filesystems, while
+# an interrupted run still keeps all but the last few measurements.
+struct PendingHistory
+    durations::Dict{String, Float64}
+    passed::Set{String}
+    failed::Set{String}
+end
+PendingHistory() = PendingHistory(Dict{String, Float64}(), Set{String}(), Set{String}())
+
+function record_test_history!(pending::PTR.Lockable{PendingHistory}, mod::Module, test::String, result, duration::Real;
+                            history_flush_every::Integer, history_key = nothing)
+    failed = !(result isa PTR.AbstractTestRecord) || PTR.anynonpass(result[])
+    batch = @lock pending begin
+        pending[].durations[test] = Float64(duration)
+        # a retried test is recorded once per attempt, and the last one is what counts
+        delete!(failed ? pending[].passed : pending[].failed, test)
+        push!(failed ? pending[].failed : pending[].passed, test)
+        length(pending[].durations) >= history_flush_every ? take_pending_history!(pending[]) : nothing
+    end
+    batch === nothing || update_test_history!(mod, batch...; history_key)
+    return nothing
+end
+
+function take_pending_history!(pending::PendingHistory)
+    batch = (copy(pending.durations), copy(pending.passed), copy(pending.failed))
+    empty!(pending.durations); empty!(pending.passed); empty!(pending.failed)
+    return batch
+end
+
+function flush_test_history!(pending::PTR.Lockable{PendingHistory}, mod::Module; history_key = nothing)
+    batch = @lock pending take_pending_history!(pending[])
+    isempty(batch[1]) || update_test_history!(mod, batch...; history_key)
+    return nothing
+end
+
+# Replace the whole history, e.g. to seed it in tests.
+function save_test_history(mod::Module, history::Tuple{Dict{String, Float64}, Set{String}};
+                        history_key = nothing)
+    history_file = get_history_file(mod, history_key)
+    try
+        with_history_lock(history_file) do
+            write_test_history(history_file, history)
+        end
+    catch e
+        @warn "Failed to save test history to $history_file" exception=e
+    end
+    return nothing
+end
+
+end
diff --git a/test/history.jl b/test/history.jl
index 072e850..1e037d9 100644
--- a/test/history.jl
+++ b/test/history.jl
@@ -1,5 +1,5 @@
 using Test
-using ParallelTestRunner: Pidfile, deserialize
+using ParallelTestRunner.TestHistory: Pidfile, deserialize
 
 history_module(name) = Module(Symbol("HistoryTest_", name))
 history_file(mod) = ParallelTestRunner.get_history_file(mod)
@@ -58,6 +58,34 @@ end
     end
 end
 
+@testset "a test passing on its retry is not marked as failed" begin
+    mod = history_module("retry")
+    remove_history(mod)
+    try
+        mktempdir() do dir
+            # fails on the first attempt, passes on the retry; both attempts land in the same
+            # pending batch, so the retry has to override the failed attempt in memory
+            marker = joinpath(dir, "flaky")
+            testsuite = Dict("flaky" => quote
+                if isfile($marker)
+                    @test true
+                else
+                    touch($marker)
+                    @test false
+                end
+            end)
+            io = IOBuffer()
+            @show_if_error io runtests(mod, ["--jobs=1"]; testsuite, retries=1, stdout=io, stderr=io)
+
+            durations, failures = ParallelTestRunner.load_test_history(mod)
+            @test haskey(durations, "flaky")
+            @test isempty(failures)
+        end
+    finally
+        remove_history(mod)
+    end
+end
+
 @testset "history is written in batches during the run" begin
     mod = history_module("batches")
     remove_history(mod)
@@ -68,7 +96,7 @@ end
         testsuite = Dict(name => :(@test true) for name in names)
         # runs after the parallel batch and inspects the history from inside the worker:
         # the batch of `history_flush_every` tests must already be on disk
-        testsuite["last"] = :(@test length(Main.ParallelTestRunner.deserialize($file)[1]) == $batch)
+        testsuite["last"] = :(@test length(Main.ParallelTestRunner.TestHistory.deserialize($file)[1]) == $batch)
         io = IOBuffer()
         @show_if_error io runtests(mod, ["--jobs=2"]; testsuite, serial=["last"], serial_position=:after,
                                    history_flush_every=batch, stdout=io, stderr=io)
@@ -103,7 +131,7 @@ end
     try
         ParallelTestRunner.save_test_history(mod, (Dict("a" => 1.0), Set{String}()))
         code = """
-            using ParallelTestRunner: Pidfile
+            using ParallelTestRunner.TestHistory: Pidfile
             Pidfile.mkpidlock($(repr(lock_file(mod))); stale_age=60) do
                 println("locked"); flush(stdout)
                 sleep(2)