diff --git a/binaries/system/readme.txt b/binaries/system/readme.txt
index 4cfba3c08e..d2a41d4e99 100644
--- a/binaries/system/readme.txt
+++ b/binaries/system/readme.txt
@@ -78,6 +78,8 @@ Advanced / diagnostic:
                     less complete. It should be enough for debugging most rejoin OOSes.
 -unique-logs        adds unix timestamp and process id to the filename of mainlog.html, interestinglog.html
                     and oos_dump.txt to prevent these files from becoming overwritten by another pyrogenesis process.
+-hashtest-full=X    whether to enable computation of full hashes in replaymode (default true). Can be disabled to improve performance.
+-hashtest-quick=X   whether to enable computation of quick hashes in replaymode (default false). Can be enabled for debugging purposes.
 
 Windows-specific:
 -wQpcTscSafe        allow timing via QueryPerformanceCounter despite the fact
diff --git a/source/main.cpp b/source/main.cpp
index a2b01cad0c..bd00fd3903 100644
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -554,7 +554,9 @@ static void RunGameOrAtlas(int argc, const char* argv[])
 			replay.Replay(
 				args.Has("serializationtest"),
 				args.Has("rejointest") ? args.Get("rejointest").ToInt() : -1,
-				args.Has("ooslog"));
+				args.Has("ooslog"),
+				!args.Has("hashtest-full") || args.Get("hashtest-full") == "true",
+				args.Has("hashtest-quick") && args.Get("hashtest-quick") == "true");
 		}
 
 		g_VFS.reset();
diff --git a/source/ps/Replay.cpp b/source/ps/Replay.cpp
index 2f91cda777..3d65474b99 100644
--- a/source/ps/Replay.cpp
+++ b/source/ps/Replay.cpp
@@ -167,7 +167,8 @@ void CReplayPlayer::CheckReplayMods(const ScriptInterface& scriptInterface, JS::
 	if (!warn.empty())
 		LOGWARNING("%s\nThe mods of the replay are:\n%s\nThese mods are enabled:\n%s", warn, ModListToString(replayMods), ModListToString(enabledMods));
 }
-void CReplayPlayer::Replay(bool serializationtest, int rejointestturn, bool ooslog)
+
+void CReplayPlayer::Replay(const bool serializationtest, const int rejointestturn, const bool ooslog, const bool testHashFull, const bool testHashQuick)
 {
 	ENSURE(m_Stream);
 
@@ -247,20 +248,7 @@ void CReplayPlayer::Replay(bool serializationtest, int rejointestturn, bool oosl
 		{
 			std::string replayHash;
 			*m_Stream >> replayHash;
-
-			bool quick = (type == "hash-quick");
-
-			if (turn % 100 == 0)
-			{
-				std::string hash;
-				bool ok = g_Game->GetSimulation2()->ComputeStateHash(hash, quick);
-				ENSURE(ok);
-				std::string hexHash = Hexify(hash);
-				if (hexHash == replayHash)
-					debug_printf("hash ok (%s)\n", hexHash.c_str());
-				else
-					debug_printf("HASH MISMATCH (%s != %s)\n", hexHash.c_str(), replayHash.c_str());
-			}
+			TestHash(type, replayHash, testHashFull, testHashQuick);
 		}
 		else if (type == "end")
 		{
@@ -307,3 +295,20 @@ void CReplayPlayer::Replay(bool serializationtest, int rejointestturn, bool oosl
 	delete &g_ProfileViewer;
 	SAFE_DELETE(g_ScriptStatsTable);
 }
+
+void CReplayPlayer::TestHash(const std::string& hashType, const std::string& replayHash, const bool testHashFull, const bool testHashQuick)
+{
+	bool quick = (hashType == "hash-quick");
+	if ((quick && !testHashQuick) || (!quick && !testHashFull))
+		return;
+
+	std::string hash;
+	ENSURE(g_Game->GetSimulation2()->ComputeStateHash(hash, quick));
+
+	std::string hexHash = Hexify(hash);
+
+	if (hexHash == replayHash)
+		debug_printf("%s ok (%s)\n", hashType.c_str(), hexHash.c_str());
+	else
+		debug_printf("%s MISMATCH (%s != %s)\n", hashType.c_str(), hexHash.c_str(), replayHash.c_str());
+}
diff --git a/source/ps/Replay.h b/source/ps/Replay.h
index fc36d9d549..7902edbe1e 100644
--- a/source/ps/Replay.h
+++ b/source/ps/Replay.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2017 Wildfire Games.
+/* Copyright (C) 2018 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -98,12 +98,13 @@ public:
 	~CReplayPlayer();
 
 	void Load(const OsPath& path);
-	void Replay(bool serializationtest, int rejointestturn, bool ooslog);
+	void Replay(const bool serializationtest, const int rejointestturn, const bool ooslog, const bool testHashFull, const bool testHashQuick);
 
 private:
 	std::istream* m_Stream;
 	CStr ModListToString(const std::vector<std::vector<CStr>>& list) const;
 	void CheckReplayMods(const ScriptInterface& scriptInterface, JS::HandleValue attribs) const;
+	void TestHash(const std::string& hashType, const std::string& replayHash, const bool testHashFull, const bool testHashQuick);
 };
 
 #endif // INCLUDED_REPLAY