diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4e6488f3c..c9afc869d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 ## 4.9.0 [unreleased]
 
+### Bug Fixes
+1. [#408](https://github.com/influxdata/influxdb-client-csharp/issues/408): Conversion of double to string can result in a loss of precision
+
 ### Dependencies
 Update dependencies:
 
diff --git a/Client/Writes/PointData.cs b/Client/Writes/PointData.cs
index 86b971c57..27042cdfe 100644
--- a/Client/Writes/PointData.cs
+++ b/Client/Writes/PointData.cs
@@ -470,10 +470,14 @@ private bool AppendFields(StringBuilder sb)
                 EscapeKey(sb, key);
                 sb.Append('=');
 
-                if (value is double || value is float)
+                if (value is float)
                 {
                     sb.Append(((IConvertible)value).ToString(CultureInfo.InvariantCulture));
                 }
+                else if (value is double)
+                {
+                    sb.Append(((IConvertible)value).ToString("G17"));
+                }
                 else if (value is uint || value is ulong || value is ushort)
                 {
                     sb.Append(((IConvertible)value).ToString(CultureInfo.InvariantCulture));
@@ -713,4 +717,4 @@ public override int GetHashCode()
             return !(left == right);
         }
     }
-}
\ No newline at end of file
+}