diff --git a/test/Makefile b/test/Makefile
index 6857e0cf..c32bf96c 100644
--- a/test/Makefile
+++ b/test/Makefile
@@ -72,6 +72,9 @@ check-3.7: check-bytecode
 	$(PYTHON) test_pythonlib.py --bytecode-3.7-run --verify-run
 	$(PYTHON) test_pythonlib.py --bytecode-3.7 --syntax-verify $(COMPILE)
 
+check-pypy37: check-bytecode
+	$(PYTHON) test_pythonlib.py --bytecode-pypy37 --verify-run
+
 #: Run working tests from Python 3.8
 check-3.8: check-bytecode
 	$(PYTHON) test_pythonlib.py --bytecode-3.8-run --verify-run
@@ -353,10 +356,14 @@ check-bytecode-pypy3.6: 7.1
 
 #: PyPy 5.0.x with Python 3.6.9
 check-bytecode-pypy3.6: 7.2 7.3
-7.3 7.2:
+
+7.2:
 	$(PYTHON) test_pythonlib.py --bytecode-pypy3.6-run --verify-run
 	$(PYTHON) test_pythonlib.py --bytecode-pypy3.6 --verify
 
+7.3:
+	$(PYTHON) test_pythonlib.py --bytecode-pypy3.7 --verify-run
+
 
 
 clean: clean-py-dis clean-dis clean-unverified
diff --git a/test/bytecode_pypy3.7/01_callback.pyc b/test/bytecode_pypy3.7/01_callback.pyc
new file mode 100644
index 00000000..a5d724ad
Binary files /dev/null and b/test/bytecode_pypy3.7/01_callback.pyc differ
diff --git a/test/simple_source/bug_pypy37/01_callback.py b/test/simple_source/bug_pypy37/01_callback.py
new file mode 100644
index 00000000..7325b4f5
--- /dev/null
+++ b/test/simple_source/bug_pypy37/01_callback.py
@@ -0,0 +1,10 @@
+"""This program is self-checking!"""
+
+
+def lcase(s):
+    return s.lower()
+
+
+l = ["xyz", "ABC"]
+l.sort(key=lcase)
+assert l == ["ABC", "xyz"]
diff --git a/test/test_pyenvlib.py b/test/test_pyenvlib.py
index 6db1cf11..fbf061e0 100755
--- a/test/test_pyenvlib.py
+++ b/test/test_pyenvlib.py
@@ -48,6 +48,7 @@ TEST_VERSIONS = (
     "pypy3.6-7.1.0",
     "pypy3.6-7.1.1",
     "pypy3.6-7.2.0",
+    "pypy3.8-7.3.7",
     "native",
 ) + tuple(python_versions)
 
diff --git a/test/test_pythonlib.py b/test/test_pythonlib.py
index a45e392b..d9e23fdc 100755
--- a/test/test_pythonlib.py
+++ b/test/test_pythonlib.py
@@ -116,6 +116,12 @@ for vers in (
         pythonlib = os.path.join(pythonlib, "__pycache__")
     test_options[key] = (os.path.join(lib_prefix, pythonlib), PYOC, pythonlib, vers)
 
+vers = 3.7
+bytecode = "bytecode_pypy%s_run" % vers
+key = "bytecode-pypy37"
+test_options[key] = (bytecode, PYC, bytecode, vers)
+
+
 # -----
 
 
diff --git a/uncompyle6/parsers/parse37.py b/uncompyle6/parsers/parse37.py
index 7b166c5f..e1e7c300 100644
--- a/uncompyle6/parsers/parse37.py
+++ b/uncompyle6/parsers/parse37.py
@@ -17,6 +17,7 @@ Python 3.7 grammar for the spark Earley-algorithm parser.
 """
 from __future__ import print_function
 
+from uncompyle6.scanners.tok import Token
 from uncompyle6.parser import PythonParserSingle, nop_func
 from spark_parser import DEFAULT_DEBUG as PARSER_DEFAULT_DEBUG
 from uncompyle6.parsers.parse37base import Python37BaseParser
diff --git a/uncompyle6/parsers/parse37base.py b/uncompyle6/parsers/parse37base.py
index a4a1650b..5d45b33e 100644
--- a/uncompyle6/parsers/parse37base.py
+++ b/uncompyle6/parsers/parse37base.py
@@ -523,15 +523,30 @@ class Python37BaseParser(PythonParser):
 
                 args_pos, args_kw = self.get_pos_kw(token)
 
-                # number of apply equiv arguments:
-                nak = (len(opname_base) - len("CALL_METHOD")) // 3
-                rule = (
-                    "call ::= expr "
-                    + ("pos_arg " * args_pos)
-                    + ("kwarg " * args_kw)
-                    + "expr " * nak
-                    + opname
-                )
+                if opname == "CALL_METHOD_KW":
+                    args_kw = token.attr
+                    rules_str = """
+                         expr ::= call_kw_pypy37
+                         pypy_kw_keys ::= LOAD_CONST
+                    """
+                    self.add_unique_doc_rules(rules_str, customize)
+                    rule = (
+                        "call_kw_pypy37 ::= expr "
+                        + ("expr " * args_kw)
+                        + " pypy_kw_keys "
+                        + opname
+                    )
+                else:
+                    args_pos, args_kw = self.get_pos_kw(token)
+                    # number of apply equiv arguments:
+                    nak = (len(opname_base) - len("CALL_METHOD")) // 3
+                    rule = (
+                        "call ::= expr "
+                        + ("expr " * args_pos)
+                        + ("kwarg " * args_kw)
+                        + "expr " * nak
+                        + opname
+                    )
                 self.add_unique_rule(rule, opname, token.attr, customize)
 
             elif opname == "CONTINUE":
diff --git a/uncompyle6/semantics/customize.py b/uncompyle6/semantics/customize.py
index 0d850ef8..249402f3 100644
--- a/uncompyle6/semantics/customize.py
+++ b/uncompyle6/semantics/customize.py
@@ -16,9 +16,9 @@
 """Isolate Python version-specific semantic actions here.
 """
 
-from uncompyle6.semantics.consts import PRECEDENCE, TABLE_R, TABLE_DIRECT
-
 from uncompyle6.parsers.treenode import SyntaxTree
+from uncompyle6.semantics.consts import INDENT_PER_LEVEL, PRECEDENCE, TABLE_R, TABLE_DIRECT
+from uncompyle6.semantics.helper import flatten_list
 from uncompyle6.scanners.tok import Token
 
 
@@ -28,9 +28,10 @@ def customize_for_version(self, is_pypy, version):
         # PyPy changes
         #######################
         TABLE_DIRECT.update({
-            'assert_pypy':	( '%|assert %c\n' ,     (1, 'assert_expr') ),
-            # This is as a result of an if transoration
-            'assert0_pypy':	( '%|assert %c\n' ,     (0, 'assert_expr') ),
+            "assert": ("%|assert %c\n", 0),
+            "assert_pypy":	( '%|assert %c\n' ,     (1, 'assert_expr') ),
+            # This is as a result of an if transformation
+            'assert0_pypy':	( '%|assert %c\n' ,     0),
 
             'assert_not_pypy':	( '%|assert not %c\n' , (1, 'assert_exp') ),
             'assert2_not_pypy':	( '%|assert not %c, %c\n' , (1, 'assert_exp'),
@@ -42,6 +43,42 @@ def customize_for_version(self, is_pypy, version):
             'assign3_pypy':        ( '%|%c, %c, %c = %c, %c, %c\n', 5, 4, 3, 0, 1, 2 ),
             'assign2_pypy':        ( '%|%c, %c = %c, %c\n', 3, 2, 0, 1),
             })
+
+        if version[:2] == (3, 7):
+
+            def n_call_kw_pypy37(node):
+                self.template_engine(("%p(", (0, 100)), node)
+                assert node[-1] == "CALL_METHOD_KW"
+                pypy_kw_keys = node[-2]
+                assert pypy_kw_keys == "pypy_kw_keys"
+
+                flat_elems = flatten_list(node[1:-2])
+                # FIXME zip pypy_kw_keys and elems
+
+                self.indent_more(INDENT_PER_LEVEL)
+                sep = ""
+
+                n = len(flat_elems)
+                kw_keys_tuple = pypy_kw_keys[0].attr
+                assert n == len(kw_keys_tuple)
+                for i in range(n):
+                    elem = flat_elems[i]
+                    assert elem == "expr"
+                    line_number = self.line_number
+                    value = self.traverse(elem)
+                    if line_number != self.line_number:
+                        sep += "\n" + self.indent + INDENT_PER_LEVEL[:-1]
+                        pass
+                    self.write(sep)
+                    self.write(f"{kw_keys_tuple[i]}={value}")
+                    sep = ", "
+                    pass
+
+                self.write(")")
+                self.prune()
+
+            self.n_call_kw_pypy37 = n_call_kw_pypy37
+
     else:
         ########################
         # Without PyPy
diff --git a/uncompyle6/version.py b/uncompyle6/version.py
index 138213a1..fed5a211 100644
--- a/uncompyle6/version.py
+++ b/uncompyle6/version.py
@@ -14,4 +14,4 @@
 # This file is suitable for sourcing inside POSIX shell as
 # well as importing into Python
 # fmt: off
-__version__="3.8.0"  # noqa
+__version__="3.8.1.dev0"  # noqa