diff --git a/spec/tags/core/file/expand_path_tags.txt b/spec/tags/core/file/expand_path_tags.txt
index d7d1127d9e9..64f3ea8e791 100644
--- a/spec/tags/core/file/expand_path_tags.txt
+++ b/spec/tags/core/file/expand_path_tags.txt
@@ -19,4 +19,4 @@ slow:File.expand_path raises an Encoding::CompatibilityError if the external enc
 slow:File.expand_path does not modify the string argument
 slow:File.expand_path does not modify a HOME string argument
 slow:File.expand_path returns a String when passed a String subclass
-fails:File.expand_path raises an Encoding::CompatibilityError if the external encoding is not compatible
+fails(force_encoding UTF-16 with possibly odd number of bytes):File.expand_path raises an Encoding::CompatibilityError if the external encoding is not compatible
diff --git a/spec/tags/optional/capi/encoding_tags.txt b/spec/tags/optional/capi/encoding_tags.txt
index c644f77843a..142104e5b5a 100644
--- a/spec/tags/optional/capi/encoding_tags.txt
+++ b/spec/tags/optional/capi/encoding_tags.txt
@@ -6,4 +6,4 @@ fails:C-API Encoding function rb_enc_get_index returns -1 for an object without
 fails:C-API Encoding function rb_enc_set_index raises an ArgumentError for a non-encoding capable object
 fails:C-API Encoding function ENCODING_SET raises an ArgumentError for a non-encoding capable object
 slow:C-API Encoding function rb_define_dummy_encoding raises EncodingError if too many encodings
-fails:C-API Encoding function rb_enc_strlen handles broken strings combines valid character and invalid character counts in UTF-16
+fails(string in UTF-16 with odd number of bytes):C-API Encoding function rb_enc_strlen handles broken strings combines valid character and invalid character counts in UTF-16