diff --git a/frontends/ParseOccam.hs b/frontends/ParseOccam.hs
index e23bb96..96f2436 100644
--- a/frontends/ParseOccam.hs
+++ b/frontends/ParseOccam.hs
@@ -1318,8 +1318,8 @@ initialIsAbbrev
            e <- expressionOfType t
            sColon
            eol
-           (e', _, _) <- constantFold e
-           return $ A.Specification m n $ A.IsExpr m A.Original t e'
+           return $ A.Specification m n $ A.IsExpr m A.Original t e
+    <?> "INITIAL IS abbreviation"
 
 isAbbrev :: OccParser A.Name -> OccParser A.Variable -> OccParser A.Specification
 isAbbrev newName oldVar
diff --git a/testcases/initial.occ b/testcases/initial.occ
new file mode 100644
index 0000000..7f73e0a
--- /dev/null
+++ b/testcases/initial.occ
@@ -0,0 +1,8 @@
+PROC P ()
+  INITIAL INT x IS 1234:
+  INITIAL []BYTE cs IS "hello, world":
+  SEQ
+    SEQ i = 0 FOR SIZE cs
+      cs[i] := 'A'
+    x := x + 1
+: