diff --git a/src/App/ExpressionParser.l b/src/App/ExpressionParser.l
index 4dce7e319d..49e6e3672c 100644
--- a/src/App/ExpressionParser.l
+++ b/src/App/ExpressionParser.l
@@ -340,7 +340,7 @@ EXPO     [eE][-+]?[0-9]+
 {DIGIT}*","{DIGIT}+{EXPO}?   COUNTCHARS; yylval.fvalue = num_change(yytext,',','.');       return yylval.fvalue == 1 ? ONE : NUM;
 {DIGIT}+{EXPO}               COUNTCHARS; yylval.fvalue = num_change(yytext,',','.');       return yylval.fvalue == 1 ? ONE : NUM;
 {DIGIT}+                     { COUNTCHARS;
-                               yylval.ivalue = strtoll( yytext, NULL, 0 );
+                               yylval.ivalue = strtoll( yytext, NULL, 10 );
                                if (yylval.ivalue == LLONG_MIN)
                                   throw Base::UnderflowError("Integer underflow");
                                else if (yylval.ivalue == LLONG_MAX)
diff --git a/src/App/lex.ExpressionParser.c b/src/App/lex.ExpressionParser.c
index 02d975762d..2916336b02 100644
--- a/src/App/lex.ExpressionParser.c
+++ b/src/App/lex.ExpressionParser.c
@@ -9572,7 +9572,7 @@ case 137:
 YY_RULE_SETUP
 #line 342 "ExpressionParser.l"
 { COUNTCHARS;
-                               yylval.ivalue = strtoll( yytext, NULL, 0 );
+                               yylval.ivalue = strtoll( yytext, NULL, 10 );
                                if (yylval.ivalue == LLONG_MIN)
                                   throw Base::UnderflowError("Integer underflow");
                                else if (yylval.ivalue == LLONG_MAX)