diff --git a/int64validator/at_least_sum_of.go b/int64validator/at_least_sum_of.go
index 1cdb040..a6b9b90 100644
--- a/int64validator/at_least_sum_of.go
+++ b/int64validator/at_least_sum_of.go
@@ -44,6 +44,7 @@ func (validator atLeastSumOfValidator) Validate(ctx context.Context, request tfs
 	}
 
 	var sumOfAttribs int64
+	var numUnknownAttribsToSum int
 
 	for _, path := range validator.attributesToSumPaths {
 		var attribToSum types.Int64
@@ -53,9 +54,22 @@ func (validator atLeastSumOfValidator) Validate(ctx context.Context, request tfs
 			return
 		}
 
+		if attribToSum.Null {
+			continue
+		}
+
+		if attribToSum.Unknown {
+			numUnknownAttribsToSum++
+			continue
+		}
+
 		sumOfAttribs += attribToSum.Value
 	}
 
+	if numUnknownAttribsToSum == len(validator.attributesToSumPaths) {
+		return
+	}
+
 	if i < sumOfAttribs {
 
 		response.Diagnostics.Append(validatordiag.AttributeValueDiagnostic(
@@ -75,7 +89,7 @@ func (validator atLeastSumOfValidator) Validate(ctx context.Context, request tfs
 //     - Is exclusively at least the sum of the given attributes.
 //
 // Null (unconfigured) and unknown (known after apply) values are skipped.
-func AtLeastSumOf(attributesToSum []*tftypes.AttributePath) tfsdk.AttributeValidator {
+func AtLeastSumOf(attributesToSum ...*tftypes.AttributePath) tfsdk.AttributeValidator {
 	return atLeastSumOfValidator{
 		attributesToSumPaths: attributesToSum,
 	}
diff --git a/int64validator/at_least_sum_of_test.go b/int64validator/at_least_sum_of_test.go
index 1f685b7..87a7360 100644
--- a/int64validator/at_least_sum_of_test.go
+++ b/int64validator/at_least_sum_of_test.go
@@ -86,6 +86,18 @@ func TestAtLeastSumOfValidator(t *testing.T) {
 				"two": tftypes.NewValue(tftypes.Number, nil),
 			},
 		},
+		"valid integer as Int64 returns error when all attributes to sum are null": {
+			val: types.Int64{Value: -1},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Number, nil),
+				"two": tftypes.NewValue(tftypes.Number, nil),
+			},
+			expectError: true,
+		},
 		"valid integer as Int64 greater than sum of attributes, when one summed attribute is unknown": {
 			val: types.Int64{Value: 10},
 			attributesToSumPaths: []*tftypes.AttributePath{
@@ -108,6 +120,29 @@ func TestAtLeastSumOfValidator(t *testing.T) {
 				"two": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
 			},
 		},
+		"valid integer as Int64 does not return error when all attributes to sum are unknown": {
+			val: types.Int64{Value: -1},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
+				"two": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
+			},
+		},
+		"error when attribute to sum is not Number": {
+			val: types.Int64{Value: 9},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Bool, true),
+				"two": tftypes.NewValue(tftypes.Number, 9),
+			},
+			expectError: true,
+		},
 	}
 
 	for name, test := range tests {
@@ -130,7 +165,7 @@ func TestAtLeastSumOfValidator(t *testing.T) {
 
 			response := tfsdk.ValidateAttributeResponse{}
 
-			AtLeastSumOf(test.attributesToSumPaths).Validate(context.Background(), request, &response)
+			AtLeastSumOf(test.attributesToSumPaths...).Validate(context.Background(), request, &response)
 
 			if !response.Diagnostics.HasError() && test.expectError {
 				t.Fatal("expected error, got no error")
diff --git a/int64validator/at_most_sum_of.go b/int64validator/at_most_sum_of.go
index 8d41f0b..4c69703 100644
--- a/int64validator/at_most_sum_of.go
+++ b/int64validator/at_most_sum_of.go
@@ -44,6 +44,7 @@ func (validator atMostSumOfValidator) Validate(ctx context.Context, request tfsd
 	}
 
 	var sumOfAttribs int64
+	var numUnknownAttribsToSum int
 
 	for _, path := range validator.attributesToSumPaths {
 		var attribToSum types.Int64
@@ -53,9 +54,22 @@ func (validator atMostSumOfValidator) Validate(ctx context.Context, request tfsd
 			return
 		}
 
+		if attribToSum.Null {
+			continue
+		}
+
+		if attribToSum.Unknown {
+			numUnknownAttribsToSum++
+			continue
+		}
+
 		sumOfAttribs += attribToSum.Value
 	}
 
+	if numUnknownAttribsToSum == len(validator.attributesToSumPaths) {
+		return
+	}
+
 	if i > sumOfAttribs {
 
 		response.Diagnostics.Append(validatordiag.AttributeValueDiagnostic(
@@ -75,7 +89,7 @@ func (validator atMostSumOfValidator) Validate(ctx context.Context, request tfsd
 //     - Is exclusively at most the sum of the given attributes.
 //
 // Null (unconfigured) and unknown (known after apply) values are skipped.
-func AtMostSumOf(attributesToSum []*tftypes.AttributePath) tfsdk.AttributeValidator {
+func AtMostSumOf(attributesToSum ...*tftypes.AttributePath) tfsdk.AttributeValidator {
 	return atMostSumOfValidator{
 		attributesToSumPaths: attributesToSum,
 	}
diff --git a/int64validator/at_most_sum_of_test.go b/int64validator/at_most_sum_of_test.go
index 5c393bf..457889f 100644
--- a/int64validator/at_most_sum_of_test.go
+++ b/int64validator/at_most_sum_of_test.go
@@ -86,6 +86,18 @@ func TestAtMostSumOfValidator(t *testing.T) {
 				"two": tftypes.NewValue(tftypes.Number, nil),
 			},
 		},
+		"valid integer as Int64 returns error when all attributes to sum are null": {
+			val: types.Int64{Value: 1},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Number, nil),
+				"two": tftypes.NewValue(tftypes.Number, nil),
+			},
+			expectError: true,
+		},
 		"valid integer as Int64 less than sum of attributes, when one summed attribute is unknown": {
 			val: types.Int64{Value: 8},
 			attributesToSumPaths: []*tftypes.AttributePath{
@@ -108,6 +120,29 @@ func TestAtMostSumOfValidator(t *testing.T) {
 				"two": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
 			},
 		},
+		"valid integer as Int64 does not return error when all attributes to sum are unknown": {
+			val: types.Int64{Value: 1},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
+				"two": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
+			},
+		},
+		"error when attribute to sum is not Number": {
+			val: types.Int64{Value: 9},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Bool, true),
+				"two": tftypes.NewValue(tftypes.Number, 9),
+			},
+			expectError: true,
+		},
 	}
 
 	for name, test := range tests {
@@ -130,7 +165,7 @@ func TestAtMostSumOfValidator(t *testing.T) {
 
 			response := tfsdk.ValidateAttributeResponse{}
 
-			AtMostSumOf(test.attributesToSumPaths).Validate(context.Background(), request, &response)
+			AtMostSumOf(test.attributesToSumPaths...).Validate(context.Background(), request, &response)
 
 			if !response.Diagnostics.HasError() && test.expectError {
 				t.Fatal("expected error, got no error")
diff --git a/int64validator/equal_to_sum_of.go b/int64validator/equal_to_sum_of.go
index e85d26f..2c3bc24 100644
--- a/int64validator/equal_to_sum_of.go
+++ b/int64validator/equal_to_sum_of.go
@@ -44,6 +44,7 @@ func (validator equalToSumOfValidator) Validate(ctx context.Context, request tfs
 	}
 
 	var sumOfAttribs int64
+	var numUnknownAttribsToSum int
 
 	for _, path := range validator.attributesToSumPaths {
 		var attribToSum types.Int64
@@ -53,11 +54,23 @@ func (validator equalToSumOfValidator) Validate(ctx context.Context, request tfs
 			return
 		}
 
+		if attribToSum.Null {
+			continue
+		}
+
+		if attribToSum.Unknown {
+			numUnknownAttribsToSum++
+			continue
+		}
+
 		sumOfAttribs += attribToSum.Value
 	}
 
-	if i != sumOfAttribs {
+	if numUnknownAttribsToSum == len(validator.attributesToSumPaths) {
+		return
+	}
 
+	if i != sumOfAttribs {
 		response.Diagnostics.Append(validatordiag.AttributeValueDiagnostic(
 			request.AttributePath,
 			validator.Description(ctx),
@@ -72,10 +85,10 @@ func (validator equalToSumOfValidator) Validate(ctx context.Context, request tfs
 // attribute value:
 //
 //     - Is a number, which can be represented by a 64-bit integer.
-//     - Is exclusively equal to the sum of the given attributes.
+//     - Is equal to the sum of the given attributes.
 //
 // Null (unconfigured) and unknown (known after apply) values are skipped.
-func EqualToSumOf(attributesToSum []*tftypes.AttributePath) tfsdk.AttributeValidator {
+func EqualToSumOf(attributesToSum ...*tftypes.AttributePath) tfsdk.AttributeValidator {
 	return equalToSumOfValidator{
 		attributesToSumPaths: attributesToSum,
 	}
diff --git a/int64validator/equal_to_sum_of_test.go b/int64validator/equal_to_sum_of_test.go
index 60a6ede..2f29178 100644
--- a/int64validator/equal_to_sum_of_test.go
+++ b/int64validator/equal_to_sum_of_test.go
@@ -87,6 +87,18 @@ func TestEqualToSumOfValidator(t *testing.T) {
 				"two": tftypes.NewValue(tftypes.Number, nil),
 			},
 		},
+		"valid integer as Int64 returns error when all attributes to sum are null": {
+			val: types.Int64{Value: 1},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Number, nil),
+				"two": tftypes.NewValue(tftypes.Number, nil),
+			},
+			expectError: true,
+		},
 		"valid integer as Int64 equal to sum of attributes, when one summed attribute is unknown": {
 			val: types.Int64{Value: 8},
 			attributesToSumPaths: []*tftypes.AttributePath{
@@ -109,6 +121,29 @@ func TestEqualToSumOfValidator(t *testing.T) {
 				"two": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
 			},
 		},
+		"valid integer as Int64 does not return error when all attributes to sum are unknown": {
+			val: types.Int64{Value: 1},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
+				"two": tftypes.NewValue(tftypes.Number, tftypes.UnknownValue),
+			},
+		},
+		"error when attribute to sum is not Number": {
+			val: types.Int64{Value: 9},
+			attributesToSumPaths: []*tftypes.AttributePath{
+				tftypes.NewAttributePath().WithAttributeName("one"),
+				tftypes.NewAttributePath().WithAttributeName("two"),
+			},
+			requestConfigRaw: map[string]tftypes.Value{
+				"one": tftypes.NewValue(tftypes.Bool, true),
+				"two": tftypes.NewValue(tftypes.Number, 9),
+			},
+			expectError: true,
+		},
 	}
 
 	for name, test := range tests {
@@ -131,7 +166,7 @@ func TestEqualToSumOfValidator(t *testing.T) {
 
 			response := tfsdk.ValidateAttributeResponse{}
 
-			EqualToSumOf(test.attributesToSumPaths).Validate(context.Background(), request, &response)
+			EqualToSumOf(test.attributesToSumPaths...).Validate(context.Background(), request, &response)
 
 			if !response.Diagnostics.HasError() && test.expectError {
 				t.Fatal("expected error, got no error")