diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellExperimentalClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellExperimentalClientCodegen.java
index 60e51162262..6e9b95aa416 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellExperimentalClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/PowerShellExperimentalClientCodegen.java
@@ -232,8 +232,8 @@ public class PowerShellExperimentalClientCodegen extends DefaultCodegen implemen
                 "System.Nullable[UInt32]",
                 "System.Nullable[UInt64]",
                 "System.Nullable[Decimal]",
-                "System.Nullable[[Single]",
-                "System.Nullable[[Double]",
+                "System.Nullable[Single]",
+                "System.Nullable[Double]",
                 "System.Nullable[Boolean]"
         ));