diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
index fe6764014a2..5b14b738f07 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PythonFastAPIServerCodegen.java
@@ -71,6 +71,7 @@ public class PythonFastAPIServerCodegen extends AbstractPythonCodegen {
     private static final int DEFAULT_SERVER_PORT = 8080;
     private static final String DEFAULT_PACKAGE_NAME = "openapi_server";
     private static final String DEFAULT_SOURCE_FOLDER = "src";
+    private static final String DEFAULT_IMPL_FOLDER = "impl";
     private static final String DEFAULT_PACKAGE_VERSION = "1.0.0";
 
     private String implPackage;
@@ -109,7 +110,7 @@ public class PythonFastAPIServerCodegen extends AbstractPythonCodegen {
         additionalProperties.put("baseSuffix", BASE_CLASS_SUFFIX);
         additionalProperties.put(CodegenConstants.SOURCE_FOLDER, DEFAULT_SOURCE_FOLDER);
         additionalProperties.put(CodegenConstants.PACKAGE_NAME, DEFAULT_PACKAGE_NAME);
-        additionalProperties.put(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE, DEFAULT_PACKAGE_NAME.concat(".impl"));
+        additionalProperties.put(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE, DEFAULT_IMPL_FOLDER);
 
         languageSpecificPrimitives.add("List");
         languageSpecificPrimitives.add("Dict");
@@ -124,7 +125,7 @@ public class PythonFastAPIServerCodegen extends AbstractPythonCodegen {
         apiPackage = "apis";
         modelPackage = "models";
         testPackage = "tests";
-        implPackage = "impl";
+        implPackage = DEFAULT_IMPL_FOLDER;
         apiTestTemplateFiles().put("api_test.mustache", ".py");
 
         cliOptions.add(new CliOption(CodegenConstants.PACKAGE_NAME, "python package name (convention: snake_case).")
@@ -153,10 +154,14 @@ public class PythonFastAPIServerCodegen extends AbstractPythonCodegen {
 
         if (additionalProperties.containsKey(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE)) {
             this.implPackage = ((String) additionalProperties.get(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE));
+            // Prefix templating value with the package name
+            additionalProperties.put(CodegenConstants.FASTAPI_IMPLEMENTATION_PACKAGE,
+                    this.packageName + "." + this.implPackage);
         }
 
         modelPackage = packageName + "." + modelPackage;
         apiPackage = packageName + "." + apiPackage;
+        implPackage = packageName + "." + implPackage;
 
         supportingFiles.add(new SupportingFile("README.mustache", "", "README.md"));
         supportingFiles.add(new SupportingFile("openapi.mustache", "", "openapi.yaml"));
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastapiCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastapiCodegenTest.java
index 2eb71268a12..9a222ac9fae 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastapiCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonFastapiCodegenTest.java
@@ -30,7 +30,7 @@ public class PythonFastapiCodegenTest {
         List<File> files = generator.opts(configurator.toClientOptInput()).generate();
         files.forEach(File::deleteOnExit);
 
-        TestUtils.assertFileExists(Paths.get(output.getAbsolutePath(), "/src", IMPL_PKG, "__init__.py"));
+        TestUtils.assertFileExists(Paths.get(output.getAbsolutePath(), "/src", "/nodesc", IMPL_PKG, "__init__.py"));
     }
 
     @Test