1 files changed, 1 insertions, 1 deletions
diff --git a/dive.h b/dive.h
index 85d4b9fa4..177897099 100644
--- a/dive.h
+++ b/dive.h
@@ -463,7 +463,7 @@ const char *monthname(int mon);
 extern const char *star_strings[];
 
 extern const char *default_filename;
-extern char *existing_filename;
+extern const char *existing_filename;
 extern const char *subsurface_default_filename(void);
 #define AIR_PERMILLE 209