--- a/get-edid/classic.c
+++ b/get-edid/classic.c
@@ -26,7 +26,7 @@ typedef byte* real_ptr;
 #define dosmemput(buffer,length,offset) memcpy(offset,buffer,length)
 
 #define display(...) if (quiet == 0) { fprintf(stderr, __VA_ARGS__); }
-int quiet;
+extern int quiet;
 
 real_ptr far_ptr_to_real_ptr( uint32 farptr )
 {
--- a/get-edid/i2c.c
+++ b/get-edid/i2c.c
@@ -15,7 +15,7 @@
 
 //Ideas (but not too much actual code) taken from i2c-tools. Thanks guys.
 
-int quiet;
+extern int quiet;
 
 #define display(...) if (quiet == 0) { fprintf(stderr, __VA_ARGS__); }