fix a pointer reference.

[flightgear.git] / src / Environment / environment_ctrl.hxx

diff --git a/src/Environment/environment_ctrl.hxx b/src/Environment/environment_ctrl.hxx
index 76b6aab20e0f1820aa21f54a6d2c8a710e0f10df..0ecf8db8bb0198bd6ef091768914dbe04e06274e 100644 (file)
--- a/src/Environment/environment_ctrl.hxx
+++ b/src/Environment/environment_ctrl.hxx
@@ -40,6 +40,7 @@
 
 // forward decls
 class SGPropertyNode;
+class SGSampleGroup;
 class FGMetar;
 
 /**