diff --git a/src/fix.h b/src/fix.h
index 4be3991f16..6f11272be6 100644
--- a/src/fix.h
+++ b/src/fix.h
@@ -196,10 +196,6 @@ class Fix : protected Pointers {
   void v_setup(int);
   void v_tally(int, int *, double, double *);
 
-  inline int sbmask(int j) {
-    return j >> SBBITS & 3;
-  }
-
   // union data struct for packing 32-bit and 64-bit ints into double bufs
   // see atom_vec.h for documentation