diff --git a/ext/em.cpp b/ext/em.cpp
index 5fe9e4298..2a578745f 100644
--- a/ext/em.cpp
+++ b/ext/em.cpp
@@ -1021,17 +1021,17 @@ const unsigned long EventMachine_t::ConnectToServer (const char *bind_addr, int
 	 */
 
 	if (!server || !*server || !port)
-		return NULL;
+		throw std::runtime_error ("invalid server or port");
 
 	int family, bind_size;
 	struct sockaddr bind_as, *bind_as_ptr = name2address (server, port, &family, &bind_size);
 	if (!bind_as_ptr)
-		return NULL;
+		throw std::runtime_error ("unable to resolve server address");
 	bind_as = *bind_as_ptr; // copy because name2address points to a static
 
 	int sd = socket (family, SOCK_STREAM, 0);
 	if (sd == INVALID_SOCKET)
-		return NULL;
+		throw std::runtime_error ("unable to create new socket");
 
 	/*
 	sockaddr_in pin;
@@ -1065,7 +1065,7 @@ const unsigned long EventMachine_t::ConnectToServer (const char *bind_addr, int
 	// Set the new socket nonblocking.
 	if (!SetSocketNonblocking (sd)) {
 		closesocket (sd);
-		return NULL;
+		throw std::runtime_error ("unable to set socket as non-blocking");
 	}
 	// Disable slow-start (Nagle algorithm).
 	int one = 1;
@@ -1078,7 +1078,7 @@ const unsigned long EventMachine_t::ConnectToServer (const char *bind_addr, int
 		struct sockaddr *bind_to = name2address (bind_addr, bind_port, &bind_to_family, &bind_to_size);
 		if (!bind_to) {
 			closesocket (sd);
-			throw std::runtime_error ("bad bind address");
+			throw std::runtime_error ("invalid bind address");
 		}
 		if (bind (sd, bind_to, bind_to_size) < 0) {
 			closesocket (sd);
diff --git a/ext/rubymain.cpp b/ext/rubymain.cpp
index 2ac9363df..ebfdaf144 100644
--- a/ext/rubymain.cpp
+++ b/ext/rubymain.cpp
@@ -32,6 +32,7 @@ Statics
 static VALUE EmModule;
 static VALUE EmConnection;
 
+static VALUE EM_eConnectionError;
 static VALUE EM_eUnknownTimerFired;
 static VALUE EM_eConnectionNotBound;
 static VALUE EM_eUnsupported;
@@ -458,10 +459,14 @@ static VALUE t_connect_server (VALUE self, VALUE server, VALUE port)
 	// Specifically, if the value of port comes in as a string rather than an integer,
 	// NUM2INT will throw a type error, but FIX2INT will generate garbage.
 
-	const unsigned long f = evma_connect_to_server (NULL, 0, StringValuePtr(server), NUM2INT(port));
-	if (!f)
-		rb_raise (rb_eRuntimeError, "no connection");
-	return ULONG2NUM (f);
+	try {
+		const unsigned long f = evma_connect_to_server (NULL, 0, StringValuePtr(server), NUM2INT(port));
+		if (!f)
+			rb_raise (EM_eConnectionError, "no connection");
+		return ULONG2NUM (f);
+	} catch (std::runtime_error e) {
+		rb_raise (EM_eConnectionError, e.what());
+	}
 }
 
 /*********************
@@ -474,15 +479,14 @@ static VALUE t_bind_connect_server (VALUE self, VALUE bind_addr, VALUE bind_port
 	// Specifically, if the value of port comes in as a string rather than an integer,
 	// NUM2INT will throw a type error, but FIX2INT will generate garbage.
 
-	long f;
 	try {
-		f = evma_connect_to_server (StringValuePtr(bind_addr), NUM2INT(bind_port), StringValuePtr(server), NUM2INT(port));
+		const unsigned long f = evma_connect_to_server (StringValuePtr(bind_addr), NUM2INT(bind_port), StringValuePtr(server), NUM2INT(port));
 		if (!f)
-			rb_raise (rb_eRuntimeError, "no connection");
+			rb_raise (EM_eConnectionError, "no connection");
+		return ULONG2NUM (f);
 	} catch (std::runtime_error e) {
-		rb_sys_fail(e.what());
+		rb_raise (EM_eConnectionError, e.what());
 	}
-	return ULONG2NUM (f);
 }
 
 /*********************
@@ -1048,7 +1052,8 @@ extern "C" void Init_rubyeventmachine()
 	EmModule = rb_define_module ("EventMachine");
 	EmConnection = rb_define_class_under (EmModule, "Connection", rb_cObject);
 
-	rb_define_class_under (EmModule, "NoHandlerForAcceptedConnection", rb_eException);
+	rb_define_class_under (EmModule, "NoHandlerForAcceptedConnection", rb_eRuntimeError);
+	EM_eConnectionError = rb_define_class_under (EmModule, "ConnectionError", rb_eRuntimeError);
 	EM_eConnectionNotBound = rb_define_class_under (EmModule, "ConnectionNotBound", rb_eRuntimeError);
 	EM_eUnknownTimerFired = rb_define_class_under (EmModule, "UnknownTimerFired", rb_eRuntimeError);
 	EM_eUnsupported = rb_define_class_under (EmModule, "Unsupported", rb_eRuntimeError);