diff --git a/default.ps1 b/default.ps1
index 49ad98627f2..c6475aa05ff 100644
--- a/default.ps1
+++ b/default.ps1
@@ -117,6 +117,7 @@ using System.Security;
 [assembly: AllowPartiallyTrustedCallersAttribute()]
 #endif
 [assembly: ComVisibleAttribute(false)]
+[assembly: CLSCompliantAttribute(true)]
 "
 
 	$dir = [System.IO.Path]::GetDirectoryName($file)
diff --git a/nant.build b/nant.build
index 18e70bfc46c..6036fc3ff2a 100644
--- a/nant.build
+++ b/nant.build
@@ -164,6 +164,7 @@
 					<attribute type="AllowPartiallyTrustedCallersAttribute" asis="true" />
 				</if>
 				<attribute type="ComVisibleAttribute" value="false" />
+				<attribute type="CLSCompliantAttribute" value="true" />
 			</attributes>
 			<references>
 				<include name="System.dll" />
diff --git a/nantdev.build b/nantdev.build
index 05ed8e4f333..60d270aa810 100644
--- a/nantdev.build
+++ b/nantdev.build
@@ -170,6 +170,7 @@
 					<attribute type="AllowPartiallyTrustedCallersAttribute" asis="true" />
 				</if>
 				<attribute type="ComVisibleAttribute" value="false" />
+				<attribute type="CLSCompliantAttribute" value="true" />
 			</attributes>
 			<references>
 				<include name="System.dll" />