diff --git a/modules/java/gen_java.py b/modules/java/gen_java.py
index a8a7b7611..ad7331478 100644
--- a/modules/java/gen_java.py
+++ b/modules/java/gen_java.py
@@ -678,7 +678,7 @@ JNIEXPORT jdoubleArray JNICALL Java_org_opencv_core_n_1minMaxLocManual
                         j_prologue.append( "Mat %s_mat = new Mat();" % a.name )
                     if "O" in a.out:
                         j_epilogue.append("utils.Mat_to_%(t)s(%(n)s_mat, %(n)s);" % {"t" : a.ctype, "n" : a.name})
-                        c_prologue.append( "%(t)s_to_Mat( %(n)s, %(n)s_mat );" % {"n" : a.name, "t" : a.ctype} )
+                        c_epilogue.append( "%(t)s_to_Mat( %(n)s, %(n)s_mat );" % {"n" : a.name, "t" : a.ctype} )
                 else:
 
                     fields = type_dict[a.ctype].get("jn_args")