diff --git a/Utilities/cfmt.h b/Utilities/cfmt.h
index fe04a36d7e..4d4067d9e6 100644
--- a/Utilities/cfmt.h
+++ b/Utilities/cfmt.h
@@ -15,6 +15,8 @@ C-style format parser. Appends formatted string to `out`, returns number of char
 template<typename Dst, typename Char, typename Src>
 usz cfmt_append(Dst& out, const Char* fmt, Src&& src)
 {
+	ensure(fmt);
+
 	const usz start_pos = out.size();
 
 	struct cfmt_context
diff --git a/rpcs3/Emu/System.cpp b/rpcs3/Emu/System.cpp
index 5b87114928..d97b323c2e 100644
--- a/rpcs3/Emu/System.cpp
+++ b/rpcs3/Emu/System.cpp
@@ -1989,6 +1989,8 @@ s32 error_code::error_report(s32 result, const char* fmt, const fmt_type_info* s
 		}
 	}
 
+	ensure(fmt);
+
 	logs::channel* channel = &sys_log;
 	const char* func = "Unknown function";