diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index d7115b9c8dbf..5267ee95a248 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -2254,7 +2254,11 @@ public CodegenOperation fromOperation(String path,
         }
         operationId = removeNonNameElementToCamelCase(operationId);
 
-        op.path = path;
+        if(path.startsWith("/")) {
+            op.path = path;
+        } else {
+            op.path = "/" + path;
+        }
         op.operationId = toOperationId(operationId);
         op.summary = escapeText(operation.getSummary());
         op.unescapedNotes = operation.getDescription();
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
index 672dd0be08ad..9fc3d600f909 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java
@@ -21,6 +21,7 @@
 import io.swagger.v3.oas.models.Components;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
+import io.swagger.v3.oas.models.PathItem;
 import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.Content;
 import io.swagger.v3.oas.models.media.MediaType;
@@ -37,8 +38,14 @@
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
-import java.lang.reflect.Method;
-import java.util.*;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Locale;
+import java.util.Map;
+import java.util.Set;
 import java.util.stream.Collectors;
 
 
@@ -224,8 +231,8 @@ public void testConsistentParameterNameAfterUniquenessRename() throws Exception
             .responses(new ApiResponses().addApiResponse("200", new ApiResponse().description("OK")));
 
         DefaultCodegen codegen = new DefaultCodegen();
-        CodegenOperation co = codegen.fromOperation("p/", "get", operation, Collections.emptyMap());
-        Assert.assertEquals(co.path, "p/");
+        CodegenOperation co = codegen.fromOperation("/some/path", "get", operation, Collections.emptyMap());
+        Assert.assertEquals(co.path, "/some/path");
         Assert.assertEquals(co.allParams.size(), 2);
         List<String> allParamsNames = co.allParams.stream().map(p -> p.paramName).collect(Collectors.toList());
         Assert.assertTrue(allParamsNames.contains("myparam"));
@@ -500,6 +507,21 @@ public void testCallbacks() {
         });
     }
 
+    @Test
+    public void testLeadingSlashIsAddedIfMissing() {
+        OpenAPI openAPI = TestUtils.createOpenAPI();
+        Operation operation1 = new Operation().operationId("op1").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")));
+        openAPI.path("/here", new PathItem().get(operation1));
+        Operation operation2 = new Operation().operationId("op2").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")));
+        openAPI.path("some/path", new PathItem().get(operation2));
+        final DefaultCodegen codegen = new DefaultCodegen();
+
+        CodegenOperation co1 = codegen.fromOperation("/here", "get", operation2, ModelUtils.getSchemas(openAPI), openAPI);
+        Assert.assertEquals(co1.path, "/here");
+        CodegenOperation co2 = codegen.fromOperation("some/path", "get", operation2, ModelUtils.getSchemas(openAPI), openAPI);
+        Assert.assertEquals(co2.path, "/some/path");
+    }
+
     private void verifyPersonDiscriminator(CodegenDiscriminator discriminator) {
         CodegenDiscriminator test = new CodegenDiscriminator();
         test.setPropertyName("$_type");
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultGeneratorTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultGeneratorTest.java
index 47dbcffd9df5..261149c40223 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultGeneratorTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultGeneratorTest.java
@@ -22,10 +22,10 @@ public class DefaultGeneratorTest {
     public void testProcessPaths() throws Exception {
         OpenAPI openAPI = TestUtils.createOpenAPI();
         openAPI.setPaths(new Paths());
-        openAPI.getPaths().addPathItem("path1/", new PathItem().get(new Operation().operationId("op1").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
-        openAPI.getPaths().addPathItem("path2/", new PathItem().get(new Operation().operationId("op2").addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
-        openAPI.getPaths().addPathItem("path3/", new PathItem().addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).get(new Operation().operationId("op3").addParametersItem(new QueryParameter().name("p2").schema(new IntegerSchema())).responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
-        openAPI.getPaths().addPathItem("path4/", new PathItem().addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).get(new Operation().operationId("op4").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
+        openAPI.getPaths().addPathItem("/path1", new PathItem().get(new Operation().operationId("op1").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
+        openAPI.getPaths().addPathItem("/path2", new PathItem().get(new Operation().operationId("op2").addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
+        openAPI.getPaths().addPathItem("/path3", new PathItem().addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).get(new Operation().operationId("op3").addParametersItem(new QueryParameter().name("p2").schema(new IntegerSchema())).responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
+        openAPI.getPaths().addPathItem("/path4", new PathItem().addParametersItem(new QueryParameter().name("p1").schema(new StringSchema())).get(new Operation().operationId("op4").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")))));
 
         ClientOptInput opts = new ClientOptInput();
         opts.setOpenAPI(openAPI);
@@ -38,13 +38,13 @@ public void testProcessPaths() throws Exception {
         Assert.assertEquals(result.size(), 1);
         List<CodegenOperation> defaultList = result.get("Default");
         Assert.assertEquals(defaultList.size(), 4);
-        Assert.assertEquals(defaultList.get(0).path, "path1/");
+        Assert.assertEquals(defaultList.get(0).path, "/path1");
         Assert.assertEquals(defaultList.get(0).allParams.size(), 0);
-        Assert.assertEquals(defaultList.get(1).path, "path2/");
+        Assert.assertEquals(defaultList.get(1).path, "/path2");
         Assert.assertEquals(defaultList.get(1).allParams.size(), 1);
-        Assert.assertEquals(defaultList.get(2).path, "path3/");
+        Assert.assertEquals(defaultList.get(2).path, "/path3");
         Assert.assertEquals(defaultList.get(2).allParams.size(), 2);
-        Assert.assertEquals(defaultList.get(3).path, "path4/");
+        Assert.assertEquals(defaultList.get(3).path, "/path4");
         Assert.assertEquals(defaultList.get(3).allParams.size(), 1);
     }
 }