diff --git a/src/tools/swap_mos.irp.f b/src/tools/swap_mos.irp.f
index bba9cb34..44b9cc50 100644
--- a/src/tools/swap_mos.irp.f
+++ b/src/tools/swap_mos.irp.f
@@ -7,11 +7,20 @@ program swap_mos
   double precision               :: x
   print *,  'MOs to swap?'
   read(*,*) i1, i2
-  do i=1,ao_num
-    x = mo_coef(i,i1)
-    mo_coef(i,i1) = mo_coef(i,i2)
-    mo_coef(i,i2) = x
-  enddo
+  if (is_complex) then
+    complex*16 :: xc
+    do i=1,ao_num
+      xc = mo_coef_complex(i,i1)
+      mo_coef_complex(i,i1) = mo_coef_complex(i,i2)
+      mo_coef_complex(i,i2) = xc
+    enddo
+  else
+    do i=1,ao_num
+      x = mo_coef(i,i1)
+      mo_coef(i,i1) = mo_coef(i,i2)
+      mo_coef(i,i2) = x
+    enddo
+  endif
   call save_mos
   
 end