Errors using Run SQL to change a password; ORA-00922

Hi

This is EM 12.1.0.4 on Linux x86_64.  I'm having trouble when trying to change the system user password across multiple databases via the Run SQL interface.  The password contains an exclamation point, and it is bound in double quotes, for example (not the real password)

alter user system identified by "SrL!8g9B5"; 

When I run this, EM responds with

PL/SQL procedure successfully completed.  BEGIN * ERROR at line 1: ORA-00922: missing or invalid option ORA-06512: at line 2

If I substitute an underscore for the exclamation point, as below, then EM completes the statement and changes the system user's password. 

alter user system identified by "SrL_8g9B5";