diff --git a/src/p_saveg.c b/src/p_saveg.c
index a3790d6f0..24d0d699b 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -1587,8 +1587,8 @@ static void SaveFadeThinker(const thinker_t *th, const UINT8 type)
 {
 	const fade_t *ht = (const void *)th;
 	WRITEUINT8(save_p, type);
-	WRITEINT32(save_p, ht->sectornum);
-	WRITEINT32(save_p, ht->ffloornum);
+	WRITEUINT32(save_p, ht->sectornum);
+	WRITEUINT32(save_p, ht->ffloornum);
 	WRITEINT32(save_p, ht->alpha);
 	WRITEINT16(save_p, ht->destvalue);
 	WRITEINT16(save_p, ht->destlightlevel);
@@ -2599,8 +2599,8 @@ static inline void LoadFadeThinker(actionf_p1 thinker)
 {
 	fade_t *ht = Z_Malloc(sizeof (*ht), PU_LEVSPEC, NULL);
 	ht->thinker.function.acp1 = thinker;
-	ht->sectornum = READINT32(save_p);
-	ht->ffloornum = READINT32(save_p);
+	ht->sectornum = READUINT32(save_p);
+	ht->ffloornum = READUINT32(save_p);
 	ht->alpha = READINT32(save_p);
 	ht->destvalue = READINT16(save_p);
 	ht->destlightlevel = READINT16(save_p);
diff --git a/src/p_spec.c b/src/p_spec.c
index 0346bdd3d..4cd9e5cb8 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -7729,8 +7729,8 @@ static void P_AddFakeFloorFader(ffloor_t *rover, size_t sectornum, size_t ffloor
 
 	d->thinker.function.acp1 = (actionf_p1)T_Fade;
 	d->rover = rover;
-	d->sectornum = (INT32)sectornum;
-	d->ffloornum = (INT32)ffloornum;
+	d->sectornum = (UINT32)sectornum;
+	d->ffloornum = (UINT32)ffloornum;
 
 	// If fading an invisible FOF whose render flags we did not yet set,
 	// initialize its alpha to 1
diff --git a/src/p_spec.h b/src/p_spec.h
index 9e602b192..b4577ff88 100644
--- a/src/p_spec.h
+++ b/src/p_spec.h
@@ -466,8 +466,8 @@ typedef struct
 {
 	thinker_t thinker;  ///< Thinker structure for effect.
 	ffloor_t *rover;    ///< Target ffloor
-	INT32 sectornum;    ///< Number of ffloor target sector
-	INT32 ffloornum;    ///< Number of ffloor of target sector
+	UINT32 sectornum;    ///< Number of ffloor target sector
+	UINT32 ffloornum;    ///< Number of ffloor of target sector
 	INT32 alpha;        ///< Internal alpha counter
 	INT16 destvalue;    ///< Transparency value to fade to
 	INT16 destlightlevel; ///< Light level to fade to