diff --git a/main/gbc/gbc_trans_ctrl.c b/main/gbc/gbc_trans_ctrl.c
index 276e5c020..92b2d37d2 100644
--- a/main/gbc/gbc_trans_ctrl.c
+++ b/main/gbc/gbc_trans_ctrl.c
@@ -960,7 +960,8 @@ void TRANS_for(void)
 
 	control_enter(RS_FOR);
 
-	TRANS_affectation(FALSE);
+	if (!TRANS_affectation(FALSE))
+		THROW(E_SYNTAX);
 
 	if (!CODE_check_pop_local_last(&local))
 		THROW("Loop variable must be local");
diff --git a/main/gbc/gbc_trans_expr.c b/main/gbc/gbc_trans_expr.c
index c03532cdb..7f09531a6 100644
--- a/main/gbc/gbc_trans_expr.c
+++ b/main/gbc/gbc_trans_expr.c
@@ -698,7 +698,7 @@ bool TRANS_affectation(bool dup)
 		look++;
 	}
 
-	if (!equal)
+	if (!equal || look == JOB->current)
 		return FALSE;
 
 	left = JOB->current;