diff --git a/magic/Magdir/windows b/magic/Magdir/windows
index 801a7936..094052d2 100644
--- a/magic/Magdir/windows
+++ b/magic/Magdir/windows
@@ -1895,3 +1895,23 @@
 # URL: https://learn.microsoft.com/en-us/previous-versions/windows/desktop/policy/registry-policy-file-format
 0	string	PReg
 >4	lelong	x	Group Policy Registry Policy, Version=%d
+
+# Microsoft Type Library Format (.TLB file)
+# Stores metadata on calling COM APIs (method parameters/etc)
+# Exists in two formats: the original (SLTG aka Type 1) and a newer format (MSFT aka Type 2)
+# SLTG: https://www.nationalarchives.gov.uk/PRONOM/fmt/1601
+# MSFT: https://www.nationalarchives.gov.uk/PRONOM/fmt/1602
+# (Pronom claims these formats are due to Borland, but that appears to be incorrect, Microsoft invented them.)
+# The MSFT format is documented here: https://gist.github.com/djhohnstein/e4a346ee1506895000ca0fa93e5a0024
+# Which is a copy of original: http://theircorp.byethost11.com/files/TypeLib.txt (but which displays incorrectly due to encoding issues)
+# The MSFT format is generated by the Windows CreateTypeLib2 API: https://learn.microsoft.com/en-us/windows/win32/api/oleauto/nf-oleauto-createtypelib2
+# The SLTG format is generated by the Windows CreateTypeLib API: https://learn.microsoft.com/en-us/windows/win32/api/oleauto/nf-oleauto-createtypelib
+#
+# Note type libraries can also be embedded as resources inside executables/DLL. No attempt is made here to detect that scenario.
+
+# Legacy SLTG format
+0	string	SLTG
+>-36	string	TYPELIB	Type Library (legacy SLTG format)
+
+# MSFT format
+0	string	MSFT\x02\x00\x01\x00	Type Library (MSFT format)