diff --git a/C/compiler.c b/C/compiler.c
index 75d5e9c47..1529072fe 100644
--- a/C/compiler.c
+++ b/C/compiler.c
@@ -872,13 +872,14 @@ c_eq(Term t1, Term t2, compiler_struct *cglobs)
   }
   /* first argument is an unbound var */
   if (IsNewVar(t1)) {
+    Int v = --cglobs->tmpreg;
     if (IsVarTerm(t2)) {
-      c_var(t2, 1, 0, 0, cglobs);
+      c_var(t2, v, 0, 0, cglobs);
     } else {
-      c_arg(1, t2, 0, 0, cglobs);
+      c_arg(v, t2, 0, 0, cglobs);
     }
     cglobs->onhead = TRUE;
-    c_var(t1, 1, 0, 0, cglobs);
+    c_var(t1, v, 0, 0, cglobs);
     cglobs->onhead = FALSE;    
   } else {
     c_var(t1, 0, 0, 0, cglobs);