diff --git a/src/parsers/expr_arith.cc b/src/parsers/expr_arith.cc
index db2f5b8d6f..7427cd933f 100644
--- a/src/parsers/expr_arith.cc
+++ b/src/parsers/expr_arith.cc
@@ -1410,7 +1410,7 @@ yyreduce:
 
   case 4:
 #line 103 "expr_arith.y"
-    { float val; oxml->search((yyvsp[0].val_str), val); (yyval.val_float) = val; }
+    { float val = 0; oxml->search((yyvsp[0].val_str), val); (yyval.val_float) = val; }
 #line 1415 "expr_arith.cc"
     break;
 
diff --git a/src/parsers/expr_arith.y b/src/parsers/expr_arith.y
index d13190c788..a5ff09b3d8 100644
--- a/src/parsers/expr_arith.y
+++ b/src/parsers/expr_arith.y
@@ -100,7 +100,7 @@ stmt:   expr                { result = static_cast<int>($1);}
         |                   { result = 0; }
         ;
 
-expr:   STRING              { float val; oxml->search($1, val); $$ = val; }
+expr:   STRING              { float val = 0; oxml->search($1, val); $$ = val; }
         | FLOAT             { $$ = $1; }
         | INTEGER           { $$ = static_cast<float>($1); }
         | expr '+' expr     { $$ = $1 + $3;}