diff --git a/test/test_pyenvlib.py b/test/test_pyenvlib.py
index 59ac9ced..2fe4f0ee 100755
--- a/test/test_pyenvlib.py
+++ b/test/test_pyenvlib.py
@@ -90,7 +90,7 @@ for vers in TEST_VERSIONS:
 
             if PYTHON_VERSION_TRIPLE > (3, 0):
                 version = version_tuple_to_str(end=2)
-                PYC = f"*.cpython-{version}.pyc"
+                PYC = "*.cpython-%s.pyc" % version
             test_options[vers] = (sys.path[-1], PYC, short_vers)
         else:
             short_vers = vers[:3]
diff --git a/uncompyle6/scanners/scanner3.py b/uncompyle6/scanners/scanner3.py
index 12709239..2f58fdbd 100644
--- a/uncompyle6/scanners/scanner3.py
+++ b/uncompyle6/scanners/scanner3.py
@@ -314,17 +314,25 @@ class Scanner3(Scanner):
         if count < 5:
             return None
 
-        collection_start = i - (count * 2)
-        assert (count * 2) <= i
+        if self.version >= (3, 5):
+            # Newer Python BUILD_MAP argument's count is a
+            # key and value pair so it is multiplied by two.
+            collection_start = i - (count * 2)
+            assert (count * 2) <= i
 
-        for j in range(collection_start, i, 2):
-            if insts[j].opname not in ("LOAD_CONST",):
-                return None
-            if insts[j + 1].opname not in ("LOAD_CONST",):
-                return None
+            for j in range(collection_start, i, 2):
+                if insts[j].opname not in ("LOAD_CONST",):
+                    return None
+                if insts[j + 1].opname not in ("LOAD_CONST",):
+                    return None
 
-        collection_start = i - (2 * count)
-        collection_enum = CONST_COLLECTIONS.index("CONST_MAP")
+            collection_start = i - (2 * count)
+            collection_enum = CONST_COLLECTIONS.index("CONST_MAP")
+        # else: Older Python count is sum of all key and value pairs
+        # Each pair is added individually like:
+        #    LOAD_CONST           ("Max-Age")
+        #    LOAD_CONST           ("max-age")
+        #    STORE_MAP
 
         # If we get here, all instructions before tokens[i] are LOAD_CONST and
         # we can replace add a boundary marker and change LOAD_CONST to
@@ -521,7 +529,7 @@ class Scanner3(Scanner):
                 if try_tokens is not None:
                     new_tokens = try_tokens
                     continue
-            elif opname in ("BUILD_MAP",):
+            elif opname in ("BUILD_MAP",) and self.version >= (3, 5):
                 try_tokens = self.bound_map_from_inst(
                     self.insts,
                     new_tokens,
diff --git a/uncompyle6/semantics/customize37.py b/uncompyle6/semantics/customize37.py
index c0b2f2f7..6102d818 100644
--- a/uncompyle6/semantics/customize37.py
+++ b/uncompyle6/semantics/customize37.py
@@ -20,6 +20,7 @@ import re
 from uncompyle6.semantics.consts import INDENT_PER_LEVEL, PRECEDENCE, TABLE_DIRECT
 from uncompyle6.semantics.helper import flatten_list
 
+# FIXME get from a newer xdis
 FSTRING_CONVERSION_MAP = {1: "!s", 2: "!r", 3: "!a", "X": ":X"}