diff --git a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/message.proto b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/message.proto
index 51160a14..65eca0d4 100644
--- a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/message.proto
+++ b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/message.proto
@@ -115,4 +115,10 @@ message Message {
   google.protobuf.DoubleValue double_value_type = 23;
   google.protobuf.Timestamp timestamp_type = 24;
   google.protobuf.Duration duration_type = 25;
+  // Description of 64-bit integer values
+  string int64_type = 26;
+  string sint64_type = 27;
+  string uint64_type = 28;
+  string fixed64_type = 29;
+  string sfixed64_type = 30;
 }
diff --git a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi.yaml b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi.yaml
index 6cb6b7fb..0f2e68fe 100644
--- a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi.yaml
+++ b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi.yaml
@@ -150,6 +150,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             responses:
                 "200":
                     description: OK
@@ -315,6 +340,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64_type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             requestBody:
                 content:
                     application/json:
@@ -459,6 +509,21 @@ components:
                 duration_type:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
+                int64_type:
+                    type: string
+                    format: int64
+                sint64_type:
+                    type: string
+                    format: sint64
+                uint64_type:
+                    type: string
+                    format: uint64
+                fixed64_type:
+                    type: string
+                    format: fixed64
+                sfixed64_type:
+                    type: string
+                    format: sfixed64
         Message_EmbMessage:
             type: object
             properties:
diff --git a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_default_response.yaml b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_default_response.yaml
index 1158893e..2c1780a7 100644
--- a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_default_response.yaml
+++ b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_default_response.yaml
@@ -150,6 +150,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             responses:
                 "200":
                     description: OK
@@ -315,6 +340,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             requestBody:
                 content:
                     application/json:
@@ -459,6 +509,21 @@ components:
                 durationType:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
+                int64Type:
+                    type: string
+                    format: int64
+                sint64Type:
+                    type: string
+                    format: sint64
+                uint64Type:
+                    type: string
+                    format: uint64
+                fixed64Type:
+                    type: string
+                    format: fixed64
+                sfixed64Type:
+                    type: string
+                    format: sfixed64
         Message_EmbMessage:
             type: object
             properties:
diff --git a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_fq_schema_naming.yaml b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_fq_schema_naming.yaml
index bd276315..7ef586a4 100644
--- a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_fq_schema_naming.yaml
+++ b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_fq_schema_naming.yaml
@@ -150,6 +150,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             responses:
                 "200":
                     description: OK
@@ -315,6 +340,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             requestBody:
                 content:
                     application/json:
@@ -475,6 +525,21 @@ components:
                 durationType:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
+                int64Type:
+                    type: string
+                    format: int64
+                sint64Type:
+                    type: string
+                    format: sint64
+                uint64Type:
+                    type: string
+                    format: uint64
+                fixed64Type:
+                    type: string
+                    format: fixed64
+                sfixed64Type:
+                    type: string
+                    format: sfixed64
         tests.protobuftypes.message.v1.Message_EmbMessage:
             type: object
             properties:
diff --git a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_json.yaml b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_json.yaml
index ae946c55..dde70f2f 100644
--- a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_json.yaml
+++ b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_json.yaml
@@ -150,6 +150,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             responses:
                 "200":
                     description: OK
@@ -315,6 +340,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             requestBody:
                 content:
                     application/json:
@@ -459,6 +509,21 @@ components:
                 durationType:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
+                int64Type:
+                    type: string
+                    format: int64
+                sint64Type:
+                    type: string
+                    format: sint64
+                uint64Type:
+                    type: string
+                    format: uint64
+                fixed64Type:
+                    type: string
+                    format: fixed64
+                sfixed64Type:
+                    type: string
+                    format: sfixed64
         Message_EmbMessage:
             type: object
             properties:
diff --git a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_string_enum.yaml b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_string_enum.yaml
index 1158893e..2c1780a7 100644
--- a/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_string_enum.yaml
+++ b/cmd/protoc-gen-openapi/examples/tests/protobuftypes/openapi_string_enum.yaml
@@ -150,6 +150,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             responses:
                 "200":
                     description: OK
@@ -315,6 +340,31 @@ paths:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
                     description: Represents a a duration between -315,576,000,000s and 315,576,000,000s (around 10000 years). Precision is in nanoseconds. 1 nanosecond is represented as 0.000000001s
+                - name: int64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: int64
+                - name: sint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sint64
+                - name: uint64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: uint64
+                - name: fixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: fixed64
+                - name: sfixed64Type
+                  in: query
+                  schema:
+                    type: string
+                    format: sfixed64
             requestBody:
                 content:
                     application/json:
@@ -459,6 +509,21 @@ components:
                 durationType:
                     pattern: ^-?(?:0|[1-9][0-9]{0,11})(?:\.[0-9]{1,9})?s$
                     type: string
+                int64Type:
+                    type: string
+                    format: int64
+                sint64Type:
+                    type: string
+                    format: sint64
+                uint64Type:
+                    type: string
+                    format: uint64
+                fixed64Type:
+                    type: string
+                    format: fixed64
+                sfixed64Type:
+                    type: string
+                    format: sfixed64
         Message_EmbMessage:
             type: object
             properties:
diff --git a/cmd/protoc-gen-openapi/generator/reflector.go b/cmd/protoc-gen-openapi/generator/reflector.go
index 31a0f930..a328c870 100644
--- a/cmd/protoc-gen-openapi/generator/reflector.go
+++ b/cmd/protoc-gen-openapi/generator/reflector.go
@@ -213,7 +213,7 @@ func (r *OpenAPIv3Reflector) schemaOrReferenceForField(field protoreflect.FieldD
 
 	case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Uint64Kind,
 		protoreflect.Sfixed64Kind, protoreflect.Fixed64Kind:
-		kindSchema = wk.NewStringSchema()
+		kindSchema = wk.NewInt64Schema(kind.String())
 
 	case protoreflect.EnumKind:
 		kindSchema = wk.NewEnumSchema(*&r.conf.EnumType, field)
diff --git a/cmd/protoc-gen-openapi/generator/wellknown/schemas.go b/cmd/protoc-gen-openapi/generator/wellknown/schemas.go
index 8840dde8..11b9c88c 100644
--- a/cmd/protoc-gen-openapi/generator/wellknown/schemas.go
+++ b/cmd/protoc-gen-openapi/generator/wellknown/schemas.go
@@ -50,6 +50,12 @@ func NewNumberSchema(format string) *v3.SchemaOrReference {
 			Schema: &v3.Schema{Type: "number", Format: format}}}
 }
 
+func NewInt64Schema(format string) *v3.SchemaOrReference {
+	return &v3.SchemaOrReference{
+		Oneof: &v3.SchemaOrReference_Schema{
+			Schema: &v3.Schema{Type: "string", Format: format}}}
+}
+
 func NewEnumSchema(enum_type *string, field protoreflect.FieldDescriptor) *v3.SchemaOrReference {
 	schema := &v3.Schema{Format: "enum"}
 	if enum_type != nil && *enum_type == "string" {