diff --git a/ChangeLog b/ChangeLog
index 076d81021..328feeb28 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2004-11-28  Alexandre Duret-Lutz  <adl@src.lip6.fr>
 
+	* src/ltltest/equals.cc (main): Add option -E.
+	* src/ltltest/parseerr.test: Use `equals -E' instead of `readltl'
+	to check the parsing of erroneous strings without being sensible
+	to the ordering for formulae in memory.
+
 	* src/tgbatest/randtgba.cc (to_float): Use strtod() instead of
 	strtof() to please Solaris 9.
 
diff --git a/src/ltltest/equals.cc b/src/ltltest/equals.cc
index 8a54d0081..b426f349e 100644
--- a/src/ltltest/equals.cc
+++ b/src/ltltest/equals.cc
@@ -34,20 +34,29 @@
 void
 syntax(char* prog)
 {
-  std::cerr << prog << " formula1 formula2" << std::endl;
+  std::cerr << prog << " [-E] formula1 formula2" << std::endl;
   exit(2);
 }
 
 int
 main(int argc, char** argv)
 {
+  bool check_first = true;
+
+  if (argc > 1 && !strcmp(argv[1], "-E"))
+    {
+      check_first = false;
+      argv[1] = argv[0];
+      ++argv;
+      --argc;
+    }
   if (argc != 3)
     syntax(argv[0]);
 
   spot::ltl::parse_error_list p1;
   spot::ltl::formula* f1 = spot::ltl::parse(argv[1], p1);
 
-  if (spot::ltl::format_parse_errors(std::cerr, argv[1], p1))
+  if (check_first && spot::ltl::format_parse_errors(std::cerr, argv[1], p1))
     return 2;
 
   spot::ltl::parse_error_list p2;
diff --git a/src/ltltest/parseerr.test b/src/ltltest/parseerr.test
index 721b37da2..413eaa047 100755
--- a/src/ltltest/parseerr.test
+++ b/src/ltltest/parseerr.test
@@ -52,25 +52,21 @@ check '+' ''
 check '/2/3/4/5 a + b /6/7/8/' ''
 
 # leading and trailing garbage are skipped
-check 'a U b c' 'binop(U, AP(a), AP(b))'
-check 'a &&& b' 'multop(And, constant(0), AP(b))'
+run 0 ./equals -E 'a U b c' 'a U b'
+run 0 ./equals -E 'a &&& b' '0 && b'
 # (check multop merging while we are at it)
-check 'a & b & c & d e' 'multop(And, AP(a), AP(b), AP(c), AP(d))'
-check 'a & (b | c) & d should work' \
-      'multop(And, AP(a), multop(Or, AP(b), AP(c)), AP(d))'
-
+run 0 ./equals -E 'a & b & c & d e' 'a & b & c & d'
+run 0 ./equals -E 'a & (b | c) & d should work' 'a & (b | c) & d'
 # Binop recovery
-check 'a U' 'constant(0)'
-check 'a U b V c R' 'constant(0)'
+run 0 ./equals -E 'a U' 0
+run 0 ./equals -E 'a U b V c R' 0
 
 # Recovery inside parentheses
-check 'a U (b c) U e R (f g <=> h)' \
-      'binop(R, binop(U, binop(U, AP(a), constant(0)), AP(e)), constant(0))'
-check 'a U ((c) U e) R (<=> f g)' \
-      'binop(R, binop(U, AP(a), binop(U, AP(c), AP(e))), constant(0))'
+run 0 ./equals -E 'a U (b c) U e R (f g <=> h)' 'a U (0) U e R (0)'
+run 0 ./equals -E 'a U ((c) U e) R (<=> f g)' 'a U ((c) U e) R (0)'
 
 # Missing parentheses
-check 'a & (a + b' 'multop(And, AP(a), multop(Or, AP(a), AP(b)))'
-check 'a & (a + b c' 'multop(And, constant(0), AP(a))'
-check 'a & (+' 'multop(And, constant(0), AP(a))'
-check 'a & ('  'multop(And, constant(0), AP(a))'
+run 0 ./equals -E 'a & (a + b' 'a & (a + b)'
+run 0 ./equals -E 'a & (a + b c' 'a & (0)'
+run 0 ./equals -E 'a & (+' 'a & (0)'
+run 0 ./equals -E 'a & ('  'a & (0)'