--- a/icc.h
+++ b/icc.h
@@ -1705,12 +1705,12 @@ extern ICCLIB_API void icm1960UCS21964WUV(icmXYZNumber *w, double *out, double *
 /* The standard D50 illuminant value */
 extern icmXYZNumber icmD50;
 extern icmXYZNumber icmD50_100;		/* Scaled to 100 */
-double icmD50_ary3[3];				/* As an array */
+extern double icmD50_ary3[3];				/* As an array */
 
 /* The standard D65 illuminant value */
 extern icmXYZNumber icmD65;
 extern icmXYZNumber icmD65_100;		/* Scaled to 100 */
-double icmD65_ary3[3];				/* As an array */
+extern double icmD65_ary3[3];				/* As an array */
 
 /* The default black value */
 extern icmXYZNumber icmBlack;