diff --git a/src/zm_image.cpp b/src/zm_image.cpp
index 7b9af0f2c..fb10126f5 100644
--- a/src/zm_image.cpp
+++ b/src/zm_image.cpp
@@ -613,7 +613,7 @@ void Image::DeColourise()
 	}
 }
 
-void Image::Hatch( Rgb colour, const Box *limits=0 )
+void Image::Hatch( Rgb colour, const Box *limits )
 {
 	assert( colours == 1 || colours == 3 );