Fix a tyop.

diff --git a/simgear/scene/sky/clouds3d/Makefile.am b/simgear/scene/sky/clouds3d/Makefile.am
index b74a64b47b2cfc00fd4ef0c2f441491397778168..a8b0b48c465df4aea687b8edca5fcc17fcafca79 100644 (file)
--- a/simgear/scene/sky/clouds3d/Makefile.am
+++ b/simgear/scene/sky/clouds3d/Makefile.am
@@ -16,7 +16,7 @@ include_HEADERS = \
        SkyUtil.hpp
 
 libsgclouds3d_a_SOURCES = \
-        $(EXTRA_SOURCE) \
+        $(EXTGL_SOURCE) \
        vec3fv.cpp \
        mat16fv.cpp \
        tri.cpp \