diff --git a/src/FsYacc.Core/fsyaccast.fs b/src/FsYacc.Core/fsyaccast.fs
index 1af148e..55c2f22 100644
--- a/src/FsYacc.Core/fsyaccast.fs
+++ b/src/FsYacc.Core/fsyaccast.fs
@@ -47,7 +47,7 @@ type Symbols = Symbol list
 
 let StringOfSym sym =
     match sym with
-    | Terminal s -> "'" ^ s ^ "'"
+    | Terminal s -> String.Concat("'", s, "'")
     | NonTerminal s -> s
 
 let OutputSym os sym = fprintf os "%s" (StringOfSym sym)
@@ -461,7 +461,9 @@ let CompilerLalrParserSpec logf (spec: ProcessedParserSpec) : CompiledSpec =
     stopWatch.Start()
 
     // Augment the grammar
-    let fakeStartNonTerminals = spec.StartSymbols |> List.map (fun nt -> "_start" ^ nt)
+    let fakeStartNonTerminals =
+        spec.StartSymbols |> List.map (fun nt -> String.Concat("_start", nt))
+
     let nonTerminals = fakeStartNonTerminals @ spec.NonTerminals
     let endOfInputTerminal = "$$"
     let dummyLookahead = "#"
@@ -620,7 +622,7 @@ let CompilerLalrParserSpec logf (spec: ProcessedParserSpec) : CompiledSpec =
 
     let StringOfSym sym =
         match sym with
-        | PTerminal s -> "'" ^ termTab.OfIndex s ^ "'"
+        | PTerminal s -> String.Concat("'", termTab.OfIndex s, "'")
         | PNonTerminal s -> ntTab.OfIndex s
 
     let OutputSym os sym = fprintf os "%s" (StringOfSym sym)