diff --git a/src/Redis.OM/Common/ExpressionParserUtilities.cs b/src/Redis.OM/Common/ExpressionParserUtilities.cs
index e42cbcb..3729b73 100644
--- a/src/Redis.OM/Common/ExpressionParserUtilities.cs
+++ b/src/Redis.OM/Common/ExpressionParserUtilities.cs
@@ -1038,6 +1038,11 @@ private static string TranslateAnyForEmbeddedObjects(MethodCallExpression exp, L
 
         private static string ValueToString(object value)
         {
+            if (value is null)
+            {
+                return "null";
+            }
+
             Type valueType = value.GetType();
 
             if (valueType == typeof(double) || Nullable.GetUnderlyingType(valueType) == typeof(double))
diff --git a/src/Redis.OM/Common/ExpressionTranslator.cs b/src/Redis.OM/Common/ExpressionTranslator.cs
index 85015d7..8e27542 100644
--- a/src/Redis.OM/Common/ExpressionTranslator.cs
+++ b/src/Redis.OM/Common/ExpressionTranslator.cs
@@ -415,7 +415,12 @@ internal static string TranslateBinaryExpression(BinaryExpression binExpression,
                 if (rightResolvesToNull)
                 {
                     dialectNeeded |= 1 << 1;
-                    return $"(ismissing({leftContent}))";
+                    return binExpression.NodeType switch
+                    {
+                        ExpressionType.Equal => $"(ismissing({leftContent}))",
+                        ExpressionType.NotEqual => $"-(ismissing({leftContent}))",
+                        _ => throw new ArgumentException($"The expression node type {binExpression.NodeType} is not supported"),
+                    };
                 }
 
                 var rightContent = ExpressionParserUtilities.GetOperandStringForQueryArgs(binExpression.Right, parameters, ref dialectNeeded, treatBooleanMemberAsUnary: true);
diff --git a/test/Redis.OM.Unit.Tests/RediSearchTests/SearchTests.cs b/test/Redis.OM.Unit.Tests/RediSearchTests/SearchTests.cs
index da0a91b..302cbf2 100644
--- a/test/Redis.OM.Unit.Tests/RediSearchTests/SearchTests.cs
+++ b/test/Redis.OM.Unit.Tests/RediSearchTests/SearchTests.cs
@@ -4156,5 +4156,22 @@ await _substitute.Received().ExecuteAsync("FT.SEARCH",
                 "0",
                 "100");
         }
+
+        [Fact]
+        public async Task TestIsNotNull()
+        {
+            _substitute.ClearSubstitute();
+            _substitute.ExecuteAsync(Arg.Any<string>(), Arg.Any<object[]>()).Returns(_mockReply);
+            var collection = new RedisCollection<ObjectWithNullableStrings>(_substitute);
+            await collection.Where(x => x.String1 != null).ToListAsync();
+            await _substitute.Received().ExecuteAsync("FT.SEARCH",
+                $"{nameof(ObjectWithNullableStrings).ToLower()}-idx",
+                "-(ismissing(@String1))",
+                "DIALECT",
+                2,
+                "LIMIT",
+                "0",
+                "100");
+        }
     }
 }
\ No newline at end of file