--- a/src/avp/win95/d3d_render.cpp
+++ b/src/avp/win95/d3d_render.cpp
@@ -2990,7 +2990,7 @@
 //#define WATER_POLY_SCALE 256
 int MeshXScale;
 int MeshZScale;
-int WaterFallBase;
+extern int WaterFallBase;
 void PostLandscapeRendering(void)
 {
 	extern int NumOnScreenBlocks;
--- a/src/opengl.c
+++ b/src/opengl.c
@@ -2796,7 +2796,7 @@
 
 int MeshXScale;
 int MeshZScale;
-int WaterFallBase;
+extern int WaterFallBase;
 
 int WaterXOrigin;
 int WaterZOrigin;