diff --git a/tests/basics/errno1.py b/tests/basics/errno1.py
index 63930b767f..d7a5ccd542 100644
--- a/tests/basics/errno1.py
+++ b/tests/basics/errno1.py
@@ -15,3 +15,7 @@ print(msg[:7], msg[-5:])
 
 # check that unknown errno is still rendered
 print(str(OSError(9999)))
+
+# this tests a failed constant lookup in errno
+errno = uerrno
+print(errno.__name__)
diff --git a/tests/basics/errno1.py.exp b/tests/basics/errno1.py.exp
index c3703df4a2..7dd22757dd 100644
--- a/tests/basics/errno1.py.exp
+++ b/tests/basics/errno1.py.exp
@@ -1,3 +1,4 @@
 <class 'int'>
 [Errno  ] EIO
 9999
+uerrno
diff --git a/tests/basics/int_constfolding.py b/tests/basics/int_constfolding.py
index 7bb5383785..158897f553 100644
--- a/tests/basics/int_constfolding.py
+++ b/tests/basics/int_constfolding.py
@@ -29,3 +29,9 @@ print(123 // 7, 123 % 7)
 print(-123 // 7, -123 % 7)
 print(123 // -7, 123 % -7)
 print(-123 // -7, -123 % -7)
+
+# won't fold so an exception can be raised at runtime
+try:
+    1 << -1
+except ValueError:
+    print('ValueError')
diff --git a/tests/basics/syntaxerror.py b/tests/basics/syntaxerror.py
index 4161de017b..843459f0bf 100644
--- a/tests/basics/syntaxerror.py
+++ b/tests/basics/syntaxerror.py
@@ -29,6 +29,10 @@ test_syntax(" a\n")
 # malformed integer literal (parser error)
 test_syntax("123z")
 
+# input doesn't match the grammar (parser error)
+test_syntax('1 or 2 or')
+test_syntax('{1:')
+
 # can't assign to literals
 test_syntax("1 = 2")
 test_syntax("'' = 1")
diff --git a/tests/cmdline/cmd_parsetree.py b/tests/cmdline/cmd_parsetree.py
index 5f698eeae3..da36c80703 100644
--- a/tests/cmdline/cmd_parsetree.py
+++ b/tests/cmdline/cmd_parsetree.py
@@ -9,3 +9,4 @@ c = 'a very long str that will not be interned'
 d = b'bytes'
 e = b'a very long bytes that will not be interned'
 f = 123456789012345678901234567890
+g = 123
diff --git a/tests/cmdline/cmd_parsetree.py.exp b/tests/cmdline/cmd_parsetree.py.exp
index d9f81d8d4c..12a1bfbe90 100644
--- a/tests/cmdline/cmd_parsetree.py.exp
+++ b/tests/cmdline/cmd_parsetree.py.exp
@@ -1,5 +1,5 @@
 ----------------
-[   4] rule(1) (n=8)
+[   4] rule(1) (n=9)
          tok(4)
 [   4]   rule(22) (n=4)
            id(i)
@@ -25,6 +25,9 @@
 [  11]   rule(5) (n=2)
            id(f)
 [  11]     literal \.\+
+[  12]   rule(5) (n=2)
+           id(g)
+           int(123)
 ----------------
 File cmdline/cmd_parsetree.py, code block '<module>' (descriptor: \.\+, bytecode @\.\+ bytes)
 Raw bytecode (code_info_size=\\d\+, bytecode_size=\\d\+):
@@ -42,6 +45,7 @@ arg names:
   bc=27 line=9
   bc=32 line=10
   bc=37 line=11
+  bc=42 line=12
 00 BUILD_TUPLE 0
 02 GET_ITER_STACK
 03 FOR_ITER 12
@@ -59,8 +63,10 @@ arg names:
 34 STORE_NAME e
 37 LOAD_CONST_OBJ \.\+
 39 STORE_NAME f
-42 LOAD_CONST_NONE
-43 RETURN_VALUE
+42 LOAD_CONST_SMALL_INT 123
+45 STORE_NAME g
+48 LOAD_CONST_NONE
+49 RETURN_VALUE
 mem: total=\\d\+, current=\\d\+, peak=\\d\+
 stack: \\d\+ out of \\d\+
 GC: total: \\d\+, used: \\d\+, free: \\d\+