diff --git a/Source/exehead/exec.c b/Source/exehead/exec.c
index b3bb87a4..8cefc0b6 100644
--- a/Source/exehead/exec.c
+++ b/Source/exehead/exec.c
@@ -648,6 +648,8 @@ static int NSISCALL ExecuteEntry(entry *entry_)
           case 8: v=v||v2; break;
           case 9: v=v&&v2; break;
           case 10: if (v2) v%=v2; else { v=0; exec_error++; } break;
+          case 11: v=v<<v2; break;
+          case 12: v=v>>v2; break;
         }
         myitoa(p,v);
       }
diff --git a/Source/script.cpp b/Source/script.cpp
index 27a17916..1c883f1c 100644
--- a/Source/script.cpp
+++ b/Source/script.cpp
@@ -4566,11 +4566,13 @@ int CEXEBuild::doCommand(int which_token, LineParser &line)
     case TOK_INTOP:
       ent.which=EW_INTOP;
       ent.offsets[0]=GetUserVarIndex(line, 1);
-      ent.offsets[3]=line.gettoken_enum(3,"+\0-\0*\0/\0|\0&\0^\0!\0||\0&&\0%\0~\0");
-      if (ent.offsets[0] < 0 || ent.offsets[3]<0 || ((ent.offsets[3] == 7 || ent.offsets[3]==11) && line.getnumtokens()>4)) PRINTHELP()
+      ent.offsets[3]=line.gettoken_enum(3,"+\0-\0*\0/\0|\0&\0^\0!\0||\0&&\0%\0<<\0>>\0~\0");
+      if (ent.offsets[0] < 0 || ent.offsets[3] < 0 ||
+        ((ent.offsets[3] == 7 || ent.offsets[3] == 13) && line.getnumtokens() > 4))
+        PRINTHELP()
       ent.offsets[1]=add_string(line.gettoken_str(2));
-      if (ent.offsets[3] != 7 && ent.offsets[3] != 11) ent.offsets[2]=add_string(line.gettoken_str(4));
-      if (ent.offsets[3] == 11) {
+      if (ent.offsets[3] != 7 && ent.offsets[3] != 13) ent.offsets[2]=add_string(line.gettoken_str(4));
+      if (ent.offsets[3] == 13) {
         ent.offsets[3]=6;
         ent.offsets[2]=add_string("0xFFFFFFFF");
       }
diff --git a/Source/tokens.cpp b/Source/tokens.cpp
index 3d3ef9e1..b456c697 100644
--- a/Source/tokens.cpp
+++ b/Source/tokens.cpp
@@ -106,7 +106,7 @@ static tokenType tokenlist[TOK__LAST] =
 {TOK_INSTDIR,"InstallDir",1,0,"default_install_directory",TP_GLOBAL},
 {TOK_INSTPROGRESSFLAGS,"InstProgressFlags",0,-1,"[flag [...]]\n    flag={smooth|colored}",TP_GLOBAL},
 {TOK_INSTTYPE,"InstType",1,0,"[un.]install_type_name | /NOCUSTOM | /CUSTOMSTRING=str | /COMPONENTSONLYONCUSTOM",TP_GLOBAL},
-{TOK_INTOP,"IntOp",3,1,"$(user_var: result) val1 OP [val2]\n    OP=(+ - * / % | & ^ ~ ! || &&)",TP_CODE},
+{TOK_INTOP,"IntOp",3,1,"$(user_var: result) val1 OP [val2]\n    OP=(+ - * / % | & ^ ~ ! || && << >>)",TP_CODE},
 {TOK_INTCMP,"IntCmp",3,2,"val1 val2 jump_if_equal [jump_if_val1_less] [jump_if_val1_more]",TP_CODE},
 {TOK_INTCMPU,"IntCmpU",3,2,"val1 val2 jump_if_equal [jump_if_val1_less] [jump_if_val1_more]",TP_CODE},
 {TOK_INTFMT,"IntFmt",3,0,"$(user_var: output) format_string input",TP_CODE},