diff --git a/docs/generators/csharp.md b/docs/generators/csharp.md
index c3b17808dc7a..102af5dbb070 100644
--- a/docs/generators/csharp.md
+++ b/docs/generators/csharp.md
@@ -88,6 +88,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 <li>List</li>
 <li>Object</li>
 <li>String</li>
+<li>System</li>
 <li>System.IO.Stream</li>
 <li>bool</li>
 <li>bool?</li>
diff --git a/docs/generators/java.md b/docs/generators/java.md
index 941e1c4e2ea9..db3cb37efc1a 100644
--- a/docs/generators/java.md
+++ b/docs/generators/java.md
@@ -197,7 +197,9 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 <li>int</li>
 <li>interface</li>
 <li>list</li>
+<li>localdate</li>
 <li>localreturntype</li>
+<li>localtime</li>
 <li>localvaraccept</li>
 <li>localvaraccepts</li>
 <li>localvarauthnames</li>
@@ -215,6 +217,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 <li>new</li>
 <li>null</li>
 <li>object</li>
+<li>offsetdatetime</li>
 <li>package</li>
 <li>private</li>
 <li>protected</li>
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java
index fac84740841c..aa8dda7151c6 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java
@@ -146,7 +146,7 @@ public AbstractCSharpCodegen() {
                         "foreach", "goto", "if", "implicit", "in", "int", "interface", "internal", "is", "lock",
                         "long", "namespace", "new", "null", "object", "operator", "out", "override", "params",
                         "private", "protected", "public", "readonly", "ref", "return", "sbyte", "sealed",
-                        "short", "sizeof", "stackalloc", "static", "string", "struct", "switch", "this", "throw",
+                        "short", "sizeof", "stackalloc", "static", "string", "struct", "switch", "system", "this", "throw",
                         "true", "try", "typeof", "uint", "ulong", "unchecked", "unsafe", "ushort", "using",
                         "virtual", "void", "volatile", "while")
         );
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
index 9dae2c164ba9..fa9a016d1d35 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractJavaCodegen.java
@@ -196,7 +196,7 @@ public AbstractJavaCodegen() {
                         "import", "public", "throws", "case", "enum", "instanceof", "return", "transient",
                         "catch", "extends", "int", "short", "try", "char", "final", "interface", "static",
                         "void", "class", "finally", "long", "strictfp", "volatile", "const", "float",
-                        "native", "super", "while", "null")
+                        "native", "super", "while", "null", "offsetdatetime", "localdate", "localtime")
         );
 
         languageSpecificPrimitives = Sets.newHashSet("String",