diff --git a/libguile/tags.h b/libguile/tags.h
index cf40c3d4d..5b0bc8c58 100644
--- a/libguile/tags.h
+++ b/libguile/tags.h
@@ -400,26 +400,20 @@ typedef union SCM { struct { scm_t_bits n; } n; } SCM;
 
 #define scm_tc7_symbol		0x05
 #define scm_tc7_variable        0x07
-
-/* couple */
 #define scm_tc7_vector		0x0d
 #define scm_tc7_wvect		0x0f
-
 #define scm_tc7_string		0x15
 #define scm_tc7_number		0x17
 #define scm_tc7_stringbuf       0x27
 #define scm_tc7_bytevector	0x4d
-
 #define scm_tc7_pointer		0x1f
 #define scm_tc7_hashtable	0x1d
 #define scm_tc7_fluid		0x25
 #define scm_tc7_dynamic_state	0x2d
-
 #define scm_tc7_frame		0x2f
 #define scm_tc7_keyword		0x35
 #define scm_tc7_unused_55	0x37
 #define scm_tc7_vm_cont		0x47
-
 #define scm_tc7_unused_17	0x3d
 #define scm_tc7_unused_21	0x3f
 #define scm_tc7_program		0x45
@@ -433,14 +427,9 @@ typedef union SCM { struct { scm_t_bits n; } n; } SCM;
 #define scm_tc7_unused_13	0x6d
 #define scm_tc7_unused_14	0x6f
 #define scm_tc7_unused_15	0x75
-#define scm_tc7_unused_16	0x77
+#define scm_tc7_unused_16	0x7f
 #define scm_tc7_port		0x7d
-
-/* There are 256 smob subtypes.  [**] If you change scm_tc7_smob, you must
- * also change the places it is hard coded in this file and possibly others.
- * Dirk:FIXME:: Any hard coded reference to scm_tc7_smob must be replaced by a
- * symbolic reference.  */
-#define scm_tc7_smob		0x7f /* DO NOT CHANGE [**] */
+#define scm_tc7_smob		0x77
 
 
 /* Definitions for tc16: */
diff --git a/module/system/base/types.scm b/module/system/base/types.scm
index a96348872..cf3c7c9d2 100644
--- a/module/system/base/types.scm
+++ b/module/system/base/types.scm
@@ -265,7 +265,7 @@ the matching bits, possibly with bitwise operations to extract it from BITS."
 (define %tc7-array #x5d)
 (define %tc7-bitvector #x5f)
 (define %tc7-port #x7d)
-(define %tc7-smob #x7f)
+(define %tc7-smob #x77)
 
 (define %tc16-bignum (+ %tc7-number (* 1 256)))
 (define %tc16-real (+ %tc7-number (* 2 256)))