diff --git a/src/main.cpp b/src/main.cpp
index 94cf3c1..24c2bc8 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -8,6 +8,7 @@
 #include <chrono>
 #include <ctime>
 #include <thread>
+#include "errno.h"
 
 #define FROM_INPUT_STRING false
 
@@ -58,11 +59,19 @@ uint32_t fileSize(string fn) {
 
     return fileSize;
 }
-
+void inputFileCheck() { 
+	if(errno == ENOENT) {
+		cout<< "VAsim Error: no such input file." << endl;
+		exit(-1);
+	}	
+}
 vector<unsigned char> file2CharVector(string fn) {
 
     // open the file:
     std::ifstream file(fn, ios::binary);
+	if(file.fail()){
+		inputFileCheck();
+	}
 
     // get its size:
     std::streampos fileSize;