diff --git a/libguile/eval.c b/libguile/eval.c
index 92f20a2c5..5fa006362 100644
--- a/libguile/eval.c
+++ b/libguile/eval.c
@@ -2292,7 +2292,7 @@ dispatch:
 			   [scm_si_hashsets + hashset];
 		      t.arg1 = SCM_CDR (t.arg1);
 		    }
-		  while (--j && SCM_NIMP (t.arg1));
+		  while (j-- && SCM_NIMP (t.arg1));
 		i &= mask;
 		end = i;
 	      }
@@ -2312,7 +2312,7 @@ dispatch:
 		      t.arg1 = SCM_CDR (t.arg1);
 		      z = SCM_CDR (z);
 		    }
-		  while (--j && SCM_NIMP (t.arg1));
+		  while (j-- && SCM_NIMP (t.arg1));
 		/* Fewer arguments than specifiers => CAR != ENV */
 		if (!(SCM_IMP (SCM_CAR (z)) || SCM_CONSP (SCM_CAR (z))))
 		  goto next_method;
diff --git a/libguile/objects.c b/libguile/objects.c
index 68836dea5..5fe685349 100644
--- a/libguile/objects.c
+++ b/libguile/objects.c
@@ -276,7 +276,7 @@ scm_mcache_lookup_cmethod (SCM cache, SCM args)
 		 [scm_si_hashsets + hashset];
 	    ls = SCM_CDR (ls);
 	  }
-	while (--j && SCM_NIMP (ls));
+	while (j-- && SCM_NIMP (ls));
       i &= mask;
       end = i;
     }
@@ -296,7 +296,7 @@ scm_mcache_lookup_cmethod (SCM cache, SCM args)
 	    ls = SCM_CDR (ls);
 	    z = SCM_CDR (z);
 	  }
-	while (--j && SCM_NIMP (ls));
+	while (j-- && SCM_NIMP (ls));
       /* Fewer arguments than specifiers => CAR != ENV */
       if (!(SCM_IMP (SCM_CAR (z)) || SCM_CONSP (SCM_CAR (z))))
 	goto next_method;