diff --git a/src/avrdude/avrdude-slic3r.conf.h b/src/avrdude/avrdude-slic3r.conf.h
index 7cc901336..905b14ee8 100644
--- a/src/avrdude/avrdude-slic3r.conf.h
+++ b/src/avrdude/avrdude-slic3r.conf.h
@@ -1,5 +1,5 @@
 /* WARN: This file is auto-generated from `avrdude-slic3r.conf` */
-unsigned char avrdude_slic3r_conf[] = {
+const unsigned char avrdude_slic3r_conf[] = {
     0x0a, 0x23, 0x0a, 0x23, 0x20, 0x54, 0x68, 0x69, 0x73, 0x20, 0x69, 0x73, 
     0x20, 0x61, 0x20, 0x62, 0x61, 0x73, 0x69, 0x63, 0x20, 0x6d, 0x69, 0x6e, 
     0x69, 0x6d, 0x61, 0x6c, 0x20, 0x63, 0x6f, 0x6e, 0x66, 0x69, 0x67, 0x20, 
@@ -1184,5 +1184,5 @@ unsigned char avrdude_slic3r_conf[] = {
     0x20, 0x20, 0x3b, 0x0a, 0x0a, 0x0a, 
     0, 0
 };
-size_t avrdude_slic3r_conf_size = 14178;
-size_t avrdude_slic3r_conf_size_yy = 14180;
+const size_t avrdude_slic3r_conf_size = 14178;
+const size_t avrdude_slic3r_conf_size_yy = 14180;
diff --git a/src/avrdude/conf-generate.cpp b/src/avrdude/conf-generate.cpp
index f2761ba22..4aa80ae0a 100644
--- a/src/avrdude/conf-generate.cpp
+++ b/src/avrdude/conf-generate.cpp
@@ -21,7 +21,7 @@ int main(int argc, char const *argv[])
     }
 
     std::cout << "/* WARN: This file is auto-generated from `" << filename << "` */" << std::endl;
-    std::cout << "unsigned char " << symbol << "[] = {";
+    std::cout << "const unsigned char " << symbol << "[] = {";
 
     char c;
     std::cout << std::hex;
@@ -34,8 +34,8 @@ int main(int argc, char const *argv[])
     std::cout << "\n    0, 0\n};\n";
 
     std::cout << std::dec;
-    std::cout << "size_t " << symbol << "_size = " << size << ";" << std::endl;
-    std::cout << "size_t " << symbol << "_size_yy = " << size + 2 << ";" << std::endl;
+    std::cout << "const size_t " << symbol << "_size = " << size << ";" << std::endl;
+    std::cout << "const size_t " << symbol << "_size_yy = " << size + 2 << ";" << std::endl;
 
     return 0;
 }