diff --git a/README.md b/README.md
index 10f15dd8..adaef115 100644
--- a/README.md
+++ b/README.md
@@ -204,7 +204,10 @@ types. The driver currently supports the following conversions:
JSON |
- time::Timespec |
+
+ time::Timespec
+ (optional)
+ |
TIMESTAMP, TIMESTAMP WITH TIME ZONE |
@@ -223,7 +226,10 @@ types. The driver currently supports the following conversions:
INT8RANGE |
- types::range::Range<Timespec> |
+
+ types::range::Range<Timespec>
+ (optional)
+ |
TSRANGE, TSTZRANGE |
@@ -259,7 +265,10 @@ types. The driver currently supports the following conversions:
INT8[], INT8[][], ... |
- types::array::ArrayBase<Option<Timespec>> |
+
+ types::array::ArrayBase<Option<Timespec>>
+ (optional)
+ |
TIMESTAMP[], TIMESTAMPTZ[], TIMESTAMP[][], ... |