diff --git a/src/newgrf.cpp b/src/newgrf.cpp
--- a/src/newgrf.cpp
+++ b/src/newgrf.cpp
@@ -5621,7 +5621,7 @@ static void GraphicsNew(ByteReader *buf)
 	uint16 offset = HasBit(type, 7) ? buf->ReadExtendedByte() : 0;
 	ClrBit(type, 7); // Clear the high bit as that only indicates whether there is an offset.
 
-	if ((type == 0x0D) && (num == 10) && _cur.grffile->is_ottdfile) {
+	if ((type == 0x0D) && (num == 10) && HasBit(_cur.grfconfig->flags, GCF_SYSTEM)) {
 		/* Special not-TTDP-compatible case used in openttd.grf
 		 * Missing shore sprites and initialisation of SPR_SHORE_BASE */
 		grfmsg(2, "GraphicsNew: Loading 10 missing shore sprites from extra grf.");
@@ -8858,7 +8858,6 @@ void LoadNewGRFFile(GRFConfig *config, u
 		if (_cur.grffile == NULL) usererror("File '%s' lost in cache.\n", filename);
 		if (stage == GLS_RESERVE && config->status != GCS_INITIALISED) return;
 		if (stage == GLS_ACTIVATION && !HasBit(config->flags, GCF_RESERVED)) return;
-		_cur.grffile->is_ottdfile = config->IsOpenTTDBaseGRF();
 	}
 
 	if (file_index > LAST_GRF_SLOT) {