diff --git a/openbsc/src/vty_interface_layer3.c b/openbsc/src/vty_interface_layer3.c
index d80f7c9..9a2c5fa 100644
--- a/openbsc/src/vty_interface_layer3.c
+++ b/openbsc/src/vty_interface_layer3.c
@@ -63,7 +63,7 @@
 		else if (c >= 'a' && c <= 'f')
 			v = 10 + (c - 'a');
 		else if (c >= 'A' && c <= 'F')
-			v = 10 + (c - 'a');
+			v = 10 + (c - 'A');
 		else
 			return -1;
 		b[i>>1] |= v << (i&1 ? 0 : 4);