Index: libopenmpt/libopenmpt_c.cpp
===================================================================
--- libopenmpt/libopenmpt_c.cpp	(revision 8244)
+++ libopenmpt/libopenmpt_c.cpp	(revision 8245)
@@ -67,12 +67,14 @@
 		err += function;
 		err += ": ";
 		err += "ERROR: ";
-		err += e.what();
+		const char * what = e.what();
+		err += what ? what : "";
 	} catch ( const std::exception & e ) {
 		err += function;
 		err += ": ";
 		err += "INTERNAL ERROR: ";
-		err += e.what();
+		const char * what = e.what();
+		err += what ? what : "";
 	} catch ( ... ) {
 		err += function;
 		err += ": ";