diff --git a/src/libromdata/Console/Dreamcast.cpp b/src/libromdata/Console/Dreamcast.cpp
index 9205590ed2..e31ad3a2e2 100644
--- a/src/libromdata/Console/Dreamcast.cpp
+++ b/src/libromdata/Console/Dreamcast.cpp
@@ -772,11 +772,7 @@ int Dreamcast::loadFieldData(void)
 		isoData = d->gdiReader->openIsoRomData(3);
 	} else {
 		// ISO object for ISO-9660 PVD
-		PartitionFilePtr isoFile = std::make_shared<PartitionFile>(
-			d->discReader.get(), 0, d->discReader->size());
-		if (isoFile->isOpen()) {
-			isoData = std::make_shared<ISO>(isoFile);
-		}
+		isoData = std::make_shared<ISO>(d->discReader);
 	}
 
 	if (isoData && isoData->isOpen()) {
diff --git a/src/libromdata/Console/Xbox360_XEX.cpp b/src/libromdata/Console/Xbox360_XEX.cpp
index f6be43d982..2050a71e68 100644
--- a/src/libromdata/Console/Xbox360_XEX.cpp
+++ b/src/libromdata/Console/Xbox360_XEX.cpp
@@ -1188,18 +1188,21 @@ const EXE *Xbox360_XEX_Private::initEXE(void)
 	// PE section, so we don't have to look anything up.
 
 	// Attempt to open the EXE section.
-	// Assuming a maximum of 8 KB for the PE headers.
-	IRpFilePtr peFile_tmp;
 #ifdef ENABLE_LIBMSPACK
 	if (!lzx_peHeader.empty()) {
-		peFile_tmp = std::make_shared<MemFile>(lzx_peHeader.data(), lzx_peHeader.size());
+		IRpFilePtr peFile_tmp = std::make_shared<MemFile>(lzx_peHeader.data(), lzx_peHeader.size());
+		if (peFile_tmp->isOpen()) {
+			EXE *const pe_exe_tmp = new EXE(peFile_tmp);
+			if (pe_exe_tmp->isOpen()) {
+				pe_exe = pe_exe_tmp;
+			} else {
+				delete pe_exe_tmp;
+			}
+		}
 	} else
 #endif /* ENABLE_LIBMSPACK */
 	{
-		peFile_tmp = std::make_shared<PartitionFile>(peReader.get(), 0, PE_HEADER_SIZE);
-	}
-	if (peFile_tmp->isOpen()) {
-		EXE *const pe_exe_tmp = new EXE(peFile_tmp);
+		EXE *const pe_exe_tmp = new EXE(peReader);
 		if (pe_exe_tmp->isOpen()) {
 			pe_exe = pe_exe_tmp;
 		} else {
diff --git a/src/libromdata/Handheld/Nintendo3DS.cpp b/src/libromdata/Handheld/Nintendo3DS.cpp
index c166df6027..5606c05c5b 100644
--- a/src/libromdata/Handheld/Nintendo3DS.cpp
+++ b/src/libromdata/Handheld/Nintendo3DS.cpp
@@ -595,8 +595,6 @@ int Nintendo3DSPrivate::openSRL(void)
 	}
 
 	// Attempt to open the SRL as if it's a new file.
-	// TODO: IRpFile implementation with offset/length, so we don't
-	// have to use both DiscReader and PartitionFile.
 
 	// Check if this content is encrypted.
 	// If it is, we'll need to create a CIAReader.
@@ -615,15 +613,8 @@ int Nintendo3DSPrivate::openSRL(void)
 		return -EIO;
 	}
 
-	// TODO: Make IDiscReader derive from IRpFile.
-	// May need to add reference counting to IRpFile...
-	RomDataPtr srlData;
-	PartitionFilePtr srlFile = std::make_shared<PartitionFile>(srlReader.get(), 0, length);
-	if (srlFile->isOpen()) {
-		// Create the NintendoDS object.
-		srlData = std::make_shared<NintendoDS>(srlFile, true);
-	}
-
+	// Create the NintendoDS object.
+	RomDataPtr srlData = std::make_shared<NintendoDS>(srlReader, true);
 	if (srlData && srlData->isOpen() && srlData->isValid()) {
 		// SRL opened successfully.
 		this->mainContent = std::move(srlData);
diff --git a/src/libromdata/Handheld/PSP.cpp b/src/libromdata/Handheld/PSP.cpp
index 9851005a50..b5c3678aae 100644
--- a/src/libromdata/Handheld/PSP.cpp
+++ b/src/libromdata/Handheld/PSP.cpp
@@ -551,9 +551,7 @@ int PSP::loadFieldData(void)
 	// TODO: Parse firmware update PARAM.SFO and EBOOT.BIN?
 
 	// ISO object for ISO-9660 PVD
-	// TODO: DiscReader overload for ISO.
-	const PartitionFilePtr ptFile = std::make_shared<PartitionFile>(d->discReader.get(), 0, d->discReader->size());
-	ISO *const isoData = new ISO(ptFile);
+	ISO *const isoData = new ISO(d->discReader);
 	if (isoData->isOpen()) {
 		// Add the fields.
 		const RomFields *const isoFields = isoData->fields();