diff --git a/src/d_clisrv.c b/src/d_clisrv.c
index b33149803..91fd6def8 100644
--- a/src/d_clisrv.c
+++ b/src/d_clisrv.c
@@ -5590,7 +5590,7 @@ static INT16 Consistancy(void)
 	// Coop desynching enemies is painful
 	if (gamestate == GS_LEVEL)
 	{
-		for (i = 0; i < PRNUMCLASS; i++)
+		for (i = 0; i < PRNUMSYNCED; i++)
 		{
 			if (i & 1)
 			{
diff --git a/src/d_main.cpp b/src/d_main.cpp
index 7df05d12f..29bb57091 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -853,8 +853,6 @@ void D_SRB2Loop(void)
 		realtics = entertic - oldentertics;
 		oldentertics = entertic;
 
-		refreshdirmenu = 0; // not sure where to put this, here as good as any?
-
 		if (demo.playback && gamestate == GS_LEVEL)
 		{
 			// Nicer place to put this.
@@ -870,8 +868,16 @@ void D_SRB2Loop(void)
 		interp = R_UsingFrameInterpolation() && !dedicated;
 		doDisplay = false;
 
-		if (realtics > 0 || singletics)
+		renderisnewtic = (realtics > 0 || singletics);
+
+		bool timeisprogressing = (!(paused || P_AutoPause()) && !hu_stopped);
+
+		if (renderisnewtic)
 		{
+			refreshdirmenu = 0;
+
+			P_ResetInterpHudRandSeed(timeisprogressing);
+
 			// don't skip more than 10 frames at a time
 			// (fadein / fadeout cause massive frame skip!)
 			if (realtics > 8)
@@ -906,19 +912,13 @@ void D_SRB2Loop(void)
 
 				doDisplay = true;
 			}
-
-			renderisnewtic = true;
-		}
-		else
-		{
-			renderisnewtic = false;
 		}
 
 		if (interp)
 		{
 			renderdeltatics = FLOAT_TO_FIXED(deltatics);
 
-			if (!(paused || P_AutoPause()) && !hu_stopped)
+			if (timeisprogressing)
 			{
 				rendertimefrac = g_time.timefrac;
 			}
@@ -938,6 +938,9 @@ void D_SRB2Loop(void)
 
 		if ((interp || doDisplay) && !frameskip)
 		{
+			if (!renderisnewtic)
+				P_ResetInterpHudRandSeed(false);
+
 			ranwipe = D_Display();
 		}
 
diff --git a/src/g_demo.c b/src/g_demo.c
index bedbf1e41..a16e5fc4a 100644
--- a/src/g_demo.c
+++ b/src/g_demo.c
@@ -364,7 +364,7 @@ void G_ReadDemoExtraData(void)
 		switch (p)
 		{
 		case DW_RNG:
-			for (i = 0; i < PRNUMCLASS; i++)
+			for (i = 0; i < PRNUMSYNCED; i++)
 			{
 				rng = READUINT32(demobuf.p);
 
@@ -507,7 +507,7 @@ void G_WriteDemoExtraData(void)
 			timeout = 16;
 			WRITEUINT8(demobuf.p, DW_RNG);
 
-			for (i = 0; i < PRNUMCLASS; i++)
+			for (i = 0; i < PRNUMSYNCED; i++)
 			{
 				WRITEUINT32(demobuf.p, P_GetRandSeed(i));
 			}
@@ -1202,7 +1202,7 @@ void G_GhostTicker(void)
 			else if (ziptic == DW_RNG)
 			{
 				INT32 i;
-				for (i = 0; i < PRNUMCLASS; i++)
+				for (i = 0; i < PRNUMSYNCED; i++)
 				{
 					g->p += 4; // RNG seed
 				}
@@ -2435,7 +2435,7 @@ void G_BeginRecording(void)
 		demotime_p = NULL;
 	}
 
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		WRITEUINT32(demobuf.p, P_GetInitSeed(i));
 	}
@@ -2899,7 +2899,7 @@ void G_LoadDemoInfo(menudemo_t *pdemo)
 		goto badreplay;
 	}
 
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		info.p += 4; // RNG seed
 	}
@@ -3028,7 +3028,7 @@ void G_DoPlayDemo(const char *defdemoname)
 	char *pdemoname;
 	UINT8 availabilities[MAXPLAYERS][MAXAVAILABILITY];
 	UINT8 version,subversion;
-	UINT32 randseed[PRNUMCLASS];
+	UINT32 randseed[PRNUMSYNCED];
 	char msg[1024];
 
 	boolean spectator, bot;
@@ -3308,7 +3308,7 @@ void G_DoPlayDemo(const char *defdemoname)
 		hu_demolap = READUINT32(demobuf.p);
 
 	// Random seed
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		randseed[i] = READUINT32(demobuf.p);
 	}
@@ -3530,7 +3530,7 @@ void G_DoPlayDemo(const char *defdemoname)
 
 	R_ExecuteSetViewSize();
 
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		P_SetRandSeed(i, randseed[i]);
 	}
@@ -3667,7 +3667,7 @@ void G_AddGhost(savebuffer_t *buffer, char *defdemoname)
 	if (flags & ATTACKING_LAP)
 		p += 4;
 
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		p += 4; // random seed
 	}
@@ -3876,7 +3876,7 @@ staffbrief_t *G_GetStaffGhostBrief(UINT8 *buffer)
 	if (flags & ATTACKING_LAP)
 		temp.lap = READUINT32(p);
 
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		p += 4; // random seed
 	}
diff --git a/src/k_hud.c b/src/k_hud.c
index af5a5f725..3378f7cf5 100644
--- a/src/k_hud.c
+++ b/src/k_hud.c
@@ -2422,8 +2422,8 @@ static void K_drawBossHealthBar(void)
 
 	randtemp = bossinfo.visualbar-(bossinfo.visualdiv/(2*FRACUNIT));
 	if (randtemp > 0)
-		randlen = M_RandomKey(randtemp)+1;
-	randsign = M_RandomChance(FRACUNIT/2);
+		randlen = P_RandomKey(PR_INTERPHUDRANDOM, randtemp)+1;
+	randsign = P_RandomChance(PR_INTERPHUDRANDOM, FRACUNIT/2);
 
 	// Right wing.
 	V_DrawScaledPatch(startx-1, starty, V_HUDTRANS|V_SLIDEIN|V_SNAPTOBOTTOM|V_SNAPTORIGHT|V_FLIP, kp_bossbar[0]);
@@ -2439,10 +2439,10 @@ static void K_drawBossHealthBar(void)
 			{
 				randtemp = bossinfo.visualbar-(bossinfo.visualdiv/(2*FRACUNIT));
 				if (randtemp > 0)
-					randlen = M_RandomKey(randtemp)+1;
+					randlen = P_RandomKey(PR_INTERPHUDRANDOM, randtemp)+1;
 				if (barstatus > 1)
 				{
-					rolrand = M_RandomKey(barstatus)+1;
+					rolrand = P_RandomKey(PR_INTERPHUDRANDOM, barstatus)+1;
 				}
 				else
 				{
diff --git a/src/m_random.c b/src/m_random.c
index 9401bb341..0d490bb5b 100644
--- a/src/m_random.c
+++ b/src/m_random.c
@@ -342,6 +342,37 @@ void P_SetRandSeedNetD(const char *rfile, INT32 rline, pr_class_t pr_class, UINT
 	rng.seed[pr_class] = seed;
 }
 
+/** Change PR_INTERPHUDRANDOM state.
+  * Used for interp-safe HUD randomisation.
+  *
+  * \sa P_SetRandSeed
+  */
+#ifndef DEBUGRANDOM
+void P_ResetInterpHudRandSeed(boolean newframe)
+{
+#else
+void P_ResetInterpHudRandSeedD(const char *rfile, INT32 rline, boolean newframe)
+{
+	CONS_Printf("P_ResetInterpHudRandSeed(%c) at: %sp %d\n", (newframe ? 'T' : 'F'), rfile, rline);
+#endif
+
+	if (newframe == true)
+	{
+		// Advance the initialisation to the current seed.
+		rng.init[PR_INTERPHUDRANDOM] = rng.seed[PR_INTERPHUDRANDOM];
+	}
+	else
+	{
+		// Rewind the seed to the last initialisation.
+		rng.seed[PR_INTERPHUDRANDOM] = rng.init[PR_INTERPHUDRANDOM];
+	}
+
+	// xorshift requires a nonzero seed
+	// this should never happen, but just in case it DOES, we check
+	if (!rng.seed[PR_INTERPHUDRANDOM])
+		rng.seed[PR_INTERPHUDRANDOM] = rng.init[PR_INTERPHUDRANDOM] = DEFAULT_SEED;
+}
+
 /** Initializes random seeds for all classes.
   * Used at the beginning of a game.
   *
@@ -354,7 +385,7 @@ void P_ClearRandom(UINT32 seed)
 
 	if (!seed) seed = DEFAULT_SEED;
 
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		P_SetRandSeed(i, seed);
 
diff --git a/src/m_random.h b/src/m_random.h
index 479ea24ef..77a3f33ce 100644
--- a/src/m_random.h
+++ b/src/m_random.h
@@ -83,6 +83,10 @@ typedef enum
 
 	PR_FUZZ, // Stability testing
 
+	PRNUMSYNCED,
+
+	PR_INTERPHUDRANDOM = PRNUMSYNCED, // Interpolation-accomodating HUD randomisation
+
 	PRNUMCLASS
 } pr_class_t;
 
@@ -132,15 +136,18 @@ UINT32 P_RandomPeek(pr_class_t pr_class);
 #define P_GetInitSeed(pr) P_GetInitSeedD(__FILE__, __LINE__, pr)
 #define P_SetRandSeed(pr, s) P_SetRandSeedD(__FILE__, __LINE__, pr, s)
 #define P_SetRandSeedNet(pr, i, s) P_SetRandSeedD(__FILE__, __LINE__, pr, i, s)
+#define P_ResetInterpHudRandSeed(newframe) P_ResetInterpHudRandSeedD(__FILE__, __LINE__, newframe)
 UINT32 P_GetRandSeedD(const char *rfile, INT32 rline, pr_class_t pr_class);
 UINT32 P_GetInitSeedD(const char *rfile, INT32 rline, pr_class_t pr_class);
 void P_SetRandSeedD(const char *rfile, INT32 rline, pr_class_t pr_class, UINT32 seed);
 void P_SetRandSeedNetD(const char *rfile, INT32 rline, pr_class_t pr_class, UINT32 init, UINT32 seed);
+void P_ResetInterpHudRandSeedD(const char *rfile, INT32 rline, boolean newframe);
 #else
 UINT32 P_GetRandSeed(pr_class_t pr_class);
 UINT32 P_GetInitSeed(pr_class_t pr_class);
 void P_SetRandSeed(pr_class_t pr_class, UINT32 seed);
 void P_SetRandSeedNet(pr_class_t pr_class, UINT32 init, UINT32 seed);
+void P_ResetInterpHudRandSeed(boolean newframe);
 #endif
 
 void P_ClearRandom(UINT32 seed);
diff --git a/src/p_saveg.c b/src/p_saveg.c
index 53e18051d..064d8fdc4 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -6354,7 +6354,7 @@ static void P_NetArchiveRNG(savebuffer_t *save)
 
 	WRITEUINT32(save->p, ARCHIVEBLOCK_RNG);
 
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		WRITEUINT32(save->p, P_GetInitSeed(i));
 		WRITEUINT32(save->p, P_GetRandSeed(i));
@@ -6368,7 +6368,7 @@ static inline void P_NetUnArchiveRNG(savebuffer_t *save)
 	if (READUINT32(save->p) != ARCHIVEBLOCK_RNG)
 		I_Error("Bad $$$.sav at archive block RNG");
 
-	for (i = 0; i < PRNUMCLASS; i++)
+	for (i = 0; i < PRNUMSYNCED; i++)
 	{
 		UINT32 init = READUINT32(save->p);
 		UINT32 seed = READUINT32(save->p);