diff --git a/sound/outputs/openal_out.cpp b/sound/outputs/openal_out.cpp
index e6d0b3ae7..f0298feb2 100644
--- a/sound/outputs/openal_out.cpp
+++ b/sound/outputs/openal_out.cpp
@@ -2,26 +2,14 @@
 #include <assert.h>
 
 #include "../../stream/filters/buffer_stream.h"
+#include "../../tools/str_exception.h"
 
 using namespace Mangle::Sound;
 
 // ---- Helper functions and classes ----
 
-class OpenAL_Exception : public std::exception
-{
-  std::string msg;
-
- public:
-
-  OpenAL_Exception(const std::string &m) : msg(m) {}
-  ~OpenAL_Exception() throw() {}
-  virtual const char* what() const throw() { return msg.c_str(); }
-};
-
 static void fail(const std::string &msg)
-{
-  throw OpenAL_Exception("OpenAL exception: " + msg);
-}
+{ throw str_exception("OpenAL exception: " + msg); }
 
 static void checkALError(const std::string &msg)
 {
diff --git a/sound/sources/audiere_source.cpp b/sound/sources/audiere_source.cpp
index 8a6b57ada..6a0776402 100644
--- a/sound/sources/audiere_source.cpp
+++ b/sound/sources/audiere_source.cpp
@@ -1,25 +1,12 @@
 #include "audiere_source.h"
 
 #include "../../stream/clients/audiere_file.h"
+#include "../../tools/str_exception.h"
 
 using namespace Mangle::Stream;
 
-// Exception handling
-class Audiere_Exception : public std::exception
-{
-  std::string msg;
-
- public:
-
-  Audiere_Exception(const std::string &m) : msg(m) {}
-  ~Audiere_Exception() throw() {}
-  virtual const char* what() const throw() { return msg.c_str(); }
-};
-
 static void fail(const std::string &msg)
-{
-  throw Audiere_Exception("Audiere exception: " + msg);
-}
+{ throw str_exception("Audiere exception: " + msg); }
 
 using namespace audiere;
 using namespace Mangle::Sound;
diff --git a/sound/sources/ffmpeg_source.cpp b/sound/sources/ffmpeg_source.cpp
index 372d1766d..5724689de 100644
--- a/sound/sources/ffmpeg_source.cpp
+++ b/sound/sources/ffmpeg_source.cpp
@@ -1,5 +1,6 @@
 #include "ffmpeg_source.h"
-#include <exception>
+
+#include "../../tools/str_exception.h"
 
 using namespace Mangle::Sound;
 
@@ -7,30 +8,8 @@ using namespace Mangle::Sound;
 // streams operated from the same thread.
 static uint8_t outBuf[AVCODEC_MAX_AUDIO_FRAME_SIZE];
 
-/// FFmpeg exception.
-class FFM_Exception : public std::exception
-{
-  std::string msg;
-
- public:
-
-  FFM_Exception(const std::string &m);
-  ~FFM_Exception() throw();
-  virtual const char* what() const throw();
-};
-
-FFM_Exception::FFM_Exception(const std::string &m)
-  : msg(m) {}
-
-const char* FFM_Exception::what() const throw()
-{ return msg.c_str(); }
-
-FFM_Exception::~FFM_Exception() throw() {}
-
 static void fail(const std::string &msg)
-{
-  throw FFM_Exception("FFMpeg exception: " + msg);
-}
+{ throw str_exception("FFMpeg exception: " + msg); }
 
 // --- Loader ---
 
diff --git a/stream/servers/file_stream.h b/stream/servers/file_stream.h
index 012cb3a78..4aeb7eeac 100644
--- a/stream/servers/file_stream.h
+++ b/stream/servers/file_stream.h
@@ -18,6 +18,9 @@ class FileStream : public StdStream
     : StdStream(&file)
     {
       file.open(name.c_str(), std::ios::binary);
+
+      if(file.fail())
+        throw str_exception("FileStream: failed to open file " + name);
     }
   ~FileStream() { file.close(); }
 };
diff --git a/stream/servers/std_stream.h b/stream/servers/std_stream.h
index d4b56a9ae..657d9303b 100644
--- a/stream/servers/std_stream.h
+++ b/stream/servers/std_stream.h
@@ -3,18 +3,20 @@
 
 #include "../stream.h"
 #include <iostream>
+#include "../../tools/str_exception.h"
 
 namespace Mangle {
 namespace Stream {
 
 /** Simplest wrapper for std::istream.
-
-    TODO: No error checking yet.
  */
 class StdStream : public Stream
 {
   std::istream *inf;
 
+  static void fail(const std::string &msg)
+    { throw str_exception("StdStream: " + msg); }
+
  public:
  StdStream(std::istream *_inf)
    : inf(_inf)
@@ -27,11 +29,17 @@ class StdStream : public Stream
   size_t read(void* buf, size_t len)
   {
     inf->read((char*)buf, len);
+    if(inf->fail())
+      fail("error reading from stream");
     return inf->gcount();
   }
 
   void seek(size_t pos)
-  { inf->seekg(pos); }
+  {
+    inf->seekg(pos);
+    if(inf->fail())
+      fail("seek error");
+  }
 
   size_t tell() const
   // Hack around the fact that ifstream->tellg() isn't const
@@ -44,6 +52,10 @@ class StdStream : public Stream
     inf->seekg(0, std::ios::end);
     size_t res = inf->tellg();
     inf->seekg(pos);
+
+    if(inf->fail())
+      fail("could not get stream size");
+
     return res;
   }
 
diff --git a/tools/str_exception.h b/tools/str_exception.h
new file mode 100644
index 000000000..39120a3f9
--- /dev/null
+++ b/tools/str_exception.h
@@ -0,0 +1,19 @@
+#ifndef __STR_EXCEPTION_H
+#define __STR_EXCEPTION_H
+
+#include <exception>
+#include <string>
+
+/// A simple exception that takes and holds a string
+class str_exception : public std::exception
+{
+  std::string msg;
+
+ public:
+
+  str_exception(const std::string &m) : msg(m) {}
+  ~str_exception() throw() {}
+  const char* what() const throw() { return msg.c_str(); }
+};
+
+#endif