diff --git a/jnius/jnius_conversion.pxi b/jnius/jnius_conversion.pxi
index 3e966d4..7c26199 100644
--- a/jnius/jnius_conversion.pxi
+++ b/jnius/jnius_conversion.pxi
@@ -76,13 +76,18 @@ cdef void populate_args(JNIEnv *j_env, tuple definition_args, jvalue *j_args, ar
         elif argtype[0] == '[':
             if py_arg is None:
                 j_args[index].l = NULL
-            else:
-                if not isinstance(py_arg, list) and \
-                        not isinstance(py_arg, tuple):
-                    raise JavaException('Expecting a python list/tuple, got '
-                            '{0!r}'.format(py_arg))
-                j_args[index].l = convert_pyarray_to_java(
-                        j_env, argtype[1:], py_arg)
+                continue
+            if isinstance(py_arg, basestring):
+                if argtype == '[B':
+                    py_arg = map(ord, py_arg)
+                elif argtype == '[C':
+                    py_arg = list(py_arg)
+            if not isinstance(py_arg, list) and \
+                    not isinstance(py_arg, tuple):
+                raise JavaException('Expecting a python list/tuple, got '
+                        '{0!r}'.format(py_arg))
+            j_args[index].l = convert_pyarray_to_java(
+                    j_env, argtype[1:], py_arg)
 
 
 cdef convert_jobject_to_python(JNIEnv *j_env, bytes definition, jobject j_object):
diff --git a/jnius/jnius_utils.pxi b/jnius/jnius_utils.pxi
index ebb1f56..7d893b4 100644
--- a/jnius/jnius_utils.pxi
+++ b/jnius/jnius_utils.pxi
@@ -198,7 +198,12 @@ cdef int calculate_score(sign_args, args, is_varargs=False) except *:
         if r[0] == '[':
 
             if arg is None:
-                return 10
+                score += 10
+                continue
+
+            if (r == '[B' or r == '[C') and isinstance(arg, basestring):
+                score += 10
+                continue
 
             if not isinstance(arg, tuple) and not isinstance(arg, list):
                 return -1