--- a/src/newgrf_debug_gui.cpp
+++ b/src/newgrf_debug_gui.cpp
@@ -156,6 +156,28 @@
 		return ro.GetVariable(&ro, var, param, avail);
 	}
 
+	/**
+	 * Allows to know the size of the persistent storage.
+	 * @param index Unused.
+	 * @param grfid Unused.
+	 * @return Size of the persistent storage in indices.
+	 */
+	virtual uint GetPSASize(uint index, uint32 grfid) const
+	{
+		return 0;
+	}
+
+	/**
+	 * Gets the first position of the array containing the persistent storage.
+	 * @param index Unused.
+	 * @param grfid Unused.
+	 * @return Pointer to the first position of the storage array or NULL if not present.
+	 */
+	virtual int32 *GetPSAFirstPosition(uint index, uint32 grfid) const
+	{
+		return NULL;
+	}
+
 protected:
 	/**
 	 * Actually execute the real resolving for a given (instance) index.
@@ -199,8 +221,6 @@
 	const NICallback *callbacks;  ///< The callbacks associated with this feature.
 	const NIVariable *variables;  ///< The variables associated with this feature.
 	const NIHelper   *helper;     ///< The class container all helper functions.
-	uint psa_size;                ///< The size of the persistent storage in indices.
-	size_t psa_offset;            ///< Offset to the array in the PSA.
 };
 
 /* Load all the NewGRF debug data; externalised as it is just a huge bunch of tables. */
@@ -348,11 +368,12 @@
 			}
 		}
 
-		if (nif->psa_size != 0) {
+		uint psa_size = nih->GetPSASize(0, 0);
+		if (psa_size != 0) {
 			this->DrawString(r, i++, "Persistent storage:");
-			assert(nif->psa_size % 4 == 0);
-			int32 *psa = (int32*)((byte*)base + nif->psa_offset);
-			for (uint j = 0; j < nif->psa_size; j += 4, psa += 4) {
+			assert(psa_size % 4 == 0);
+			int32 *psa = nih->GetPSAFirstPosition(0, 0);
+			for (uint j = 0; j < psa_size; j += 4, psa += 4) {
 				this->DrawString(r, i++, "  %i: %i %i %i %i", j, psa[0], psa[1], psa[2], psa[3]);
 			}
 		}

--- a/src/table/newgrf_debug_data.h
+++ b/src/table/newgrf_debug_data.h
@@ -74,8 +74,6 @@
 	_nic_vehicles,
 	_niv_vehicles,
 	new NIHVehicle(),
-	0,
-	0
 };
 
 
@@ -132,8 +130,6 @@
 	_nic_stations,
 	_niv_stations,
 	new NIHStation(),
-	0,
-	0
 };
 
 
@@ -193,8 +189,6 @@
 	_nic_house,
 	_niv_house,
 	new NIHHouse(),
-	0,
-	0
 };
 
 
@@ -239,8 +233,6 @@
 	_nic_industrytiles,
 	_niv_industrytiles,
 	new NIHIndustryTile(),
-	0,
-	0
 };
 
 
@@ -299,6 +291,13 @@
 	const void *GetSpec(uint index) const                { return GetIndustrySpec(Industry::Get(index)->type); }
 	void SetStringParameters(uint index) const           { this->SetSimpleStringParameters(STR_INDUSTRY_NAME, index); }
 	void Resolve(ResolverObject *ro, uint32 index) const { extern void GetIndustryResolver(ResolverObject *ro, uint index); GetIndustryResolver(ro, index); }
+	uint GetPSASize(uint index, uint32 grfid) const      { return cpp_lengthof(Industry, psa.storage); }
+
+	int32 *GetPSAFirstPosition(uint index, uint32 grfid) const
+	{
+		const void *base = this->GetInstance(index);
+		return (int32*)((byte*)base + cpp_offsetof(Industry, psa.storage));
+	}
 };
 
 static const NIFeature _nif_industry = {
@@ -306,8 +305,6 @@
 	_nic_industries,
 	_niv_industries,
 	new NIHIndustry(),
-	cpp_lengthof(Industry, psa.storage),
-	cpp_offsetof(Industry, psa.storage)
 };
 
 
@@ -357,8 +354,6 @@
 	_nic_objects,
 	_niv_objects,
 	new NIHObject(),
-	0,
-	0
 };
 
 
@@ -385,8 +380,6 @@
 	NULL,
 	_niv_railtypes,
 	new NIHRailType(),
-	0,
-	0
 };
 
 
@@ -415,8 +408,6 @@
 	_nic_airporttiles,
 	_niv_industrytiles, // Yes, they share this (at least now)
 	new NIHAirportTile(),
-	0,
-	0
 };
 
 
@@ -449,8 +440,6 @@
 	NULL,
 	_niv_towns,
 	new NIHTown(),
-	0,
-	0
 };
 
 /** Table with all NIFeatures. */