diff --git a/projects/VC7.1/FlightGear.vcproj b/projects/VC7.1/FlightGear.vcproj
index 9f9163440..2e808f4d4 100755
--- a/projects/VC7.1/FlightGear.vcproj
+++ b/projects/VC7.1/FlightGear.vcproj
@@ -2301,6 +2301,12 @@
 			<File
 				RelativePath="..\..\src\Environment\fgmetar.hxx">
 			</File>
+			<File
+				RelativePath="..\..\src\Environment\precipitation_mgr.cxx">
+			</File>
+			<File
+				RelativePath="..\..\src\Environment\precipitation_mgr.hxx">
+			</File>
 		</Filter>
 		<Filter
 			Name="Lib_Model"