diff --git a/biostools/analyzers.py b/biostools/analyzers.py
index 6f61c9a..03ff8a8 100644
--- a/biostools/analyzers.py
+++ b/biostools/analyzers.py
@@ -1516,9 +1516,9 @@ class IBMSurePathAnalyzer(Analyzer):
 
 		self._ibm_pattern = re.compile(
 			b'''\\(\\(CC\\)\\)  CCOOPPYYRRIIGGHHTT  (?:IIBBMM  CCOORRPPOORRAATTIIOONN  11998811,,  ([0-9])\\1([0-9])\\2([0-9])\\3([0-9])\\4|11998811,,  ([0-9])\\5([0-9])\\6([0-9])\\7([0-9])\\8  IIBBMM  CCOORRPPOORRAATTIIOONN)  (?:--  )?AALLLL  RRIIGGHHTTSS  RREESSEERRVVEEDD|'''
-			b'''\\(C\\) COPYRIGHT (?:IBM CORPORATION 1981, [0-9]{4}|1981, [0-9]{4} IBM CORPORATION) (?:- )?ALL RIGHTS RESERVED[ \\x0D\\x0A]*\\x00'''
+			b'''\\(C\\) COPYRIGHT (?:IBM CORPORATION 1981, [0-9]{4}|1981, [0-9]{4} IBM CORPORATION) (?:- )?ALL RIGHTS RESERVED[ \\x0D\\x0A]*[\\x00\\xFF]'''
 		)
-		self._ibm_later_pattern = re.compile(b'''\\xAA{8}\\x55{8}IBM PC Co\\. BIOS ''')
+		self._ibm_later_pattern = re.compile(b'''\\xAA{8}\\x55{8}IBM PC Co\\. BIOS |PS/1 POWER MANAGEMENT\\x00''')
 		self._surepath_pattern = re.compile(b'''SurePath BIOS Version ([\\x20-\\x7E]+)(?:[\\x0D\\x0A\\x00]+([\\x20-\\x7E]+)?)?''')
 		self._apricot_pattern = re.compile(b'''@\\(#\\)(?:Apricot .*|XEN-PC) BIOS [\\x20-\\x7E]+''')
 		self._apricot_version_pattern = re.compile(b'''@\\(#\\)Version [\\x20-\\x7E]+''')