diff --git a/inputsource.cpp b/inputsource.cpp
index 64f7193..bccaf21 100644
--- a/inputsource.cpp
+++ b/inputsource.cpp
@@ -12,15 +12,17 @@ InputSource::InputSource(const char *filename, int fft_size) {
     m_fft_size = fft_size;
 
     m_file = fopen(filename, "rb");
-    // TODO: throw exception if failed
+    if (m_file == nullptr)
+        throw "Error opening file";
 
     struct stat sb;
-    fstat(fileno(m_file), &sb);
-    // TODO: throw exception if failed
+    if (fstat(fileno(m_file), &sb) != 0)
+        throw "Error fstating file";
     m_file_size = sb.st_size;
 
     m_data = (fftwf_complex*)mmap(NULL, m_file_size, PROT_READ, MAP_SHARED, fileno(m_file), 0);
-    // TODO: throw exception if failed
+    if (m_data == 0)
+        throw "Error mmapping file";
 
     m_fftw_in = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex) * m_fft_size);
     m_fftw_out = (fftwf_complex*)fftwf_malloc(sizeof(fftwf_complex) * m_fft_size);
diff --git a/main.cpp b/main.cpp
index 9525b58..8a60a52 100644
--- a/main.cpp
+++ b/main.cpp
@@ -8,6 +8,8 @@
 
 class MyApp: public wxApp
 {
+private:
+    InputSource *m_input_source;
 public:
     virtual bool OnInit();
 };
@@ -49,9 +51,14 @@ bool MyApp::OnInit()
             fft_size = size;
     }
 
-    InputSource *is = new InputSource(argv[1], fft_size);
+    try {
+        m_input_source = new InputSource(argv[1], fft_size);
+    } catch (const char *msg) {
+        printf("%s\n", msg);
+        return false;
+    }
 
-    wxImagePanel *impanel = new wxImagePanel(frame, is);
+    wxImagePanel *impanel = new wxImagePanel(frame, m_input_source);
     sizer->Add(impanel, 1, wxALL | wxEXPAND, 0);
     frame->SetSizer(sizer);