diff --git a/src/farchive.cpp b/src/farchive.cpp
index 1b41faef7..a589df50a 100644
--- a/src/farchive.cpp
+++ b/src/farchive.cpp
@@ -575,6 +575,20 @@ bool FCompressedMemFile::IsOpen () const
 	return !!m_Buffer;
 }
 
+void FCompressedMemFile::GetSizes(unsigned int &compressed, unsigned int &uncompressed) const
+{
+	if (m_ImplodedBuffer != NULL)
+	{
+		compressed = BigLong(*(unsigned int *)m_ImplodedBuffer);
+		uncompressed = BigLong(*(unsigned int *)(m_ImplodedBuffer + 4));
+	}
+	else
+	{
+		compressed = 0;
+		uncompressed = m_BufferSize;
+	}
+}
+
 FPNGChunkFile::FPNGChunkFile (FILE *file, DWORD id)
 	: FCompressedFile (file, EWriting, true, false), m_ChunkID (id)
 {
diff --git a/src/farchive.h b/src/farchive.h
index 5062b7ba7..329b448db 100644
--- a/src/farchive.h
+++ b/src/farchive.h
@@ -124,6 +124,7 @@ public:
 	bool Reopen ();	// Re-opens imploded file for reading only
 	void Close ();
 	bool IsOpen () const;
+	void GetSizes(unsigned int &one, unsigned int &two) const;
 
 	void Serialize (FArchive &arc);
 
diff --git a/src/g_level.cpp b/src/g_level.cpp
index 903a9a6c5..c51b58a66 100644
--- a/src/g_level.cpp
+++ b/src/g_level.cpp
@@ -1757,6 +1757,21 @@ void G_ReadSnapshots (PNGHandle *png)
 	png->File->ResetFilePtr();
 }
 
+//==========================================================================
+
+CCMD(listsnapshots)
+{
+	for (unsigned i = 0; i < wadlevelinfos.Size(); ++i)
+	{
+		FCompressedMemFile *snapshot = wadlevelinfos[i].snapshot;
+		if (snapshot != NULL)
+		{
+			unsigned int comp, uncomp;
+			snapshot->GetSizes(comp, uncomp);
+			Printf("%s (%u -> %u bytes)\n", wadlevelinfos[i].mapname, comp, uncomp);
+		}
+	}
+}
 
 //==========================================================================
 //