diff --git a/source/app.d b/source/app.d
index 1c4b745..604f62d 100644
--- a/source/app.d
+++ b/source/app.d
@@ -1,5 +1,6 @@
 import std.array : array, replace;
 import std.datetime : Clock;
+import std.file : exists, isFile;
 import std.format : format;
 import std.getopt : defaultGetoptPrinter, getopt;
 import std.json : JSONValue;
@@ -35,8 +36,11 @@ void main(string[] args)
              "mode" : "direct",
              "type_dm" : "any",
              "itdLPxx_bcl" : "true"]);
-
-    loadSubstitutionFile(substitutionFileName);
+    
+    if (substitutionFileName.exists && substitutionFileName.isFile)
+    {
+        loadSubstitutionFile(substitutionFileName);
+    }
 
     auto currentTime = Clock.currTime;
     JSONValue j = ["time" : "%02s:%02s".format(currentTime.hour, currentTime.minute)];
diff --git a/source/substitution.d b/source/substitution.d
index d743fe9..9275705 100644
--- a/source/substitution.d
+++ b/source/substitution.d
@@ -4,19 +4,11 @@ public:
 
 void loadSubstitutionFile(string fileName)
 {
-    import std.file : slurp, exists, isFile;
+    import std.file : slurp;
     import std.algorithm.iteration : each;
-
-    if (fileName.exists && fileName.isFile)
-    {
-        auto data = slurp!(string, string)(fileName, `"%s" = "%s"`);
-        map = (string[string]).init;
-        data.each!(pair => map[pair[0]] = pair[1]);
-    }
-    else
-    {
-        map = (string[string]).init;
-    }
+    auto data = slurp!(string, string)(fileName, `"%s" = "%s"`);
+    map = (string[string]).init;
+    data.each!(pair => map[pair[0]] = pair[1]);
 }
 
 auto substitute(string s) @safe nothrow