diff --git a/src/OpenTelemetry.Exporter.Geneva/GenevaExporterOptions.cs b/src/OpenTelemetry.Exporter.Geneva/GenevaExporterOptions.cs
index c24f76a894..809f08d214 100644
--- a/src/OpenTelemetry.Exporter.Geneva/GenevaExporterOptions.cs
+++ b/src/OpenTelemetry.Exporter.Geneva/GenevaExporterOptions.cs
@@ -105,7 +105,12 @@ public IReadOnlyDictionary<string, object> PrepopulatedFields
                     case string vs:
                         break;
                     default:
-                        throw new ArgumentException($"Type: {entry.Value.GetType()} is not supported. Only bool, byte, sbyte, short, ushort, int, uint, long, ulong, float, double, and string are the supported types for PrepopulatedFields values.");
+                        if (entry.Value == null)
+                        {
+                            throw new ArgumentNullException(entry.Key, $"{nameof(this.PrepopulatedFields)} must not contain null values.");
+                        }
+
+                        throw new ArgumentException($"Type `{entry.Value.GetType()}` (key = `{entry.Key}`) is not allowed. Only bool, byte, sbyte, short, ushort, int, uint, long, ulong, float, double, and string are supported.");
                 }
 
                 copy[entry.Key] = val; // shallow copy
diff --git a/test/OpenTelemetry.Exporter.Geneva.Tests/GenevaTraceExporterTests.cs b/test/OpenTelemetry.Exporter.Geneva.Tests/GenevaTraceExporterTests.cs
index cf4b58bd6b..7ebfa8b279 100644
--- a/test/OpenTelemetry.Exporter.Geneva.Tests/GenevaTraceExporterTests.cs
+++ b/test/OpenTelemetry.Exporter.Geneva.Tests/GenevaTraceExporterTests.cs
@@ -54,6 +54,19 @@ public void GenevaTraceExporter_constructor_Invalid_Input()
                 });
             });
 
+            // null value in the PrepopulatedFields
+            Assert.Throws<ArgumentNullException>(() =>
+            {
+                using var exporter = new GenevaTraceExporter(new GenevaExporterOptions
+                {
+                    ConnectionString = "EtwSession=OpenTelemetry",
+                    PrepopulatedFields = new Dictionary<string, object>
+                    {
+                        ["cloud.roleVer"] = null,
+                    },
+                });
+            });
+
             // unsupported types(char) for PrepopulatedFields
             Assert.Throws<ArgumentException>(() =>
             {