diff --git a/modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache b/modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache
index bad3fbfa9cb2..996c435c84ac 100644
--- a/modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache
@@ -511,7 +511,17 @@ namespace {{packageName}}.Client
                     }
                     catch (Exception ex)
                     {
+                        {{#throwOnAnyError}}
+                        // 4xx/5xx are left to ExceptionFactory, like the ErrorException check above
+                        if ((int)response.StatusCode < 400)
+                        {
+                            var error = ex.InnerException != null ? ex.InnerException : ex;
+                            throw new ApiException((int)response.StatusCode, string.Format("Error calling {0}: {1}", request.Resource, error.Message), response.Content, ToApiResponse(response).Headers, error);
+                        }
+                        {{/throwOnAnyError}}
+                        {{^throwOnAnyError}}
                         throw ex.InnerException != null ? ex.InnerException : ex;
+                        {{/throwOnAnyError}}
                     }
                 }
                 else if (typeof(T).Name == "Stream") // for binary response
diff --git a/modules/openapi-generator/src/main/resources/csharp/ApiClient.v790.mustache b/modules/openapi-generator/src/main/resources/csharp/ApiClient.v790.mustache
index d2f74ed945d4..bc111a73c080 100644
--- a/modules/openapi-generator/src/main/resources/csharp/ApiClient.v790.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp/ApiClient.v790.mustache
@@ -503,7 +503,17 @@ namespace {{packageName}}.Client
                     }
                     catch (Exception ex)
                     {
+                        {{#throwOnAnyError}}
+                        // 4xx/5xx are left to ExceptionFactory, like the ErrorException check above
+                        if ((int)response.StatusCode < 400)
+                        {
+                            var error = ex.InnerException != null ? ex.InnerException : ex;
+                            throw new ApiException((int)response.StatusCode, string.Format("Error calling {0}: {1}", request.Resource, error.Message), response.Content, ToApiResponse(response).Headers, error);
+                        }
+                        {{/throwOnAnyError}}
+                        {{^throwOnAnyError}}
                         throw ex.InnerException != null ? ex.InnerException : ex;
+                        {{/throwOnAnyError}}
                     }
                 }
                 else if (typeof(T).Name == "Stream") // for binary response
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharpnetcore/CSharpClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharpnetcore/CSharpClientCodegenTest.java
index f4d3bb56ba5d..61087564e760 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharpnetcore/CSharpClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/csharpnetcore/CSharpClientCodegenTest.java
@@ -448,6 +448,46 @@ public void testUserAgentIsNotUrlEncoded() throws IOException {
         }
     }
 
+    @Test
+    public void testThrowOnAnyErrorWrapsOneOfDeserializationFailure() throws IOException {
+        // both restsharp ApiClient templates: the default one and the useIntForTimeout v7.9.0 fallback
+        for (boolean useIntForTimeout : new boolean[]{false, true}) {
+            for (boolean throwOnAnyError : new boolean[]{false, true}) {
+                File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+                output.deleteOnExit();
+                final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/petstore.yaml");
+                final DefaultGenerator defaultGenerator = new DefaultGenerator();
+                final ClientOptInput clientOptInput = new ClientOptInput();
+                clientOptInput.openAPI(openAPI);
+                CSharpClientCodegen cSharpClientCodegen = new CSharpClientCodegen();
+                cSharpClientCodegen.setLibrary("restsharp");
+                cSharpClientCodegen.setOutputDir(output.getAbsolutePath());
+                cSharpClientCodegen.additionalProperties().put("useIntForTimeout", useIntForTimeout);
+                cSharpClientCodegen.additionalProperties().put("throwOnAnyError", throwOnAnyError);
+                clientOptInput.config(cSharpClientCodegen);
+                defaultGenerator.opts(clientOptInput);
+
+                Map<String, File> files = defaultGenerator.generate().stream()
+                        .collect(Collectors.toMap(File::getPath, Function.identity()));
+
+                File apiClient = files
+                        .get(Paths.get(output.getAbsolutePath(), "src", "Org.OpenAPITools", "Client", "ApiClient.cs").toString());
+                assertNotNull(apiClient);
+                String wrapped = "throw new ApiException((int)response.StatusCode, string.Format(\"Error calling {0}: {1}\", request.Resource, error.Message), response.Content, ToApiResponse(response).Headers, error);";
+                // 4xx/5xx must still reach ExceptionFactory, so only lower status codes are wrapped here
+                String wrappedBelow400 = "if ((int)response.StatusCode < 400) { var error = ex.InnerException != null ? ex.InnerException : ex; " + wrapped + " }";
+                String rethrown = "throw ex.InnerException != null ? ex.InnerException : ex;";
+                if (throwOnAnyError) {
+                    assertFileContains(apiClient.toPath(), wrappedBelow400);
+                    assertFileNotContains(apiClient.toPath(), rethrown);
+                } else {
+                    assertFileContains(apiClient.toPath(), rethrown);
+                    assertFileNotContains(apiClient.toPath(), wrapped);
+                }
+            }
+        }
+    }
+
     @Test
     public void testSelectHeaderAcceptKeepsAllTypesJsonFirst() throws IOException {
         File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
diff --git a/samples/client/petstore/csharp/restsharp/net4.7/MultipleFrameworks/src/Org.OpenAPITools/Client/ApiClient.cs b/samples/client/petstore/csharp/restsharp/net4.7/MultipleFrameworks/src/Org.OpenAPITools/Client/ApiClient.cs
index 58091fdfa71e..5d4eab7fb08f 100644
--- a/samples/client/petstore/csharp/restsharp/net4.7/MultipleFrameworks/src/Org.OpenAPITools/Client/ApiClient.cs
+++ b/samples/client/petstore/csharp/restsharp/net4.7/MultipleFrameworks/src/Org.OpenAPITools/Client/ApiClient.cs
@@ -508,7 +508,12 @@ private async Task<ApiResponse<T>> ExecClientAsync<T>(Func<RestClient, Task<Rest
                     }
                     catch (Exception ex)
                     {
-                        throw ex.InnerException != null ? ex.InnerException : ex;
+                        // 4xx/5xx are left to ExceptionFactory, like the ErrorException check above
+                        if ((int)response.StatusCode < 400)
+                        {
+                            var error = ex.InnerException != null ? ex.InnerException : ex;
+                            throw new ApiException((int)response.StatusCode, string.Format("Error calling {0}: {1}", request.Resource, error.Message), response.Content, ToApiResponse(response).Headers, error);
+                        }
                     }
                 }
                 else if (typeof(T).Name == "Stream") // for binary response