diff --git a/src/compiler/isaspec/encode.py b/src/compiler/isaspec/encode.py
index 8daa1ff9f5e..85de3b7a62c 100755
--- a/src/compiler/isaspec/encode.py
+++ b/src/compiler/isaspec/encode.py
@@ -133,9 +133,12 @@ class Case(object):
         self.expr = None
         if case.expr is not None:
             self.expr = isa.expressions[case.expr]
-        self.fieldnames = re.findall(r"{([a-zA-Z0-9_]+)}", case.display)
+        self.fieldnames = re.findall(r"{([a-zA-Z0-9_:]+)}", case.display)
         self.append_forced(bitset)
 
+        # remove special fieldname properties e.g. :align=
+        self.fieldnames = list(map(lambda name: name.split(':')[0], self.fieldnames))
+
     # Handle fields which don't appear in display template but have
     # force="true"
     def append_forced(self, bitset):