diff --git a/source/fail.c b/source/fail.c
index f68e941..befe6b0 100644
--- a/source/fail.c
+++ b/source/fail.c
@@ -41,7 +41,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "platform.h"
 #include "fail.h"
 
-char *fail_programName = "";
+const char *fail_programName = "";
 
 void fail( const char *messagePtr, ... )
 {
diff --git a/source/fail.h b/source/fail.h
index e981473..f163d3c 100644
--- a/source/fail.h
+++ b/source/fail.h
@@ -35,7 +35,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 =============================================================================*/
 
-extern char *fail_programName;
+extern const char *fail_programName;
 
 void fail( const char *, ... );