diff --git a/alethzero/Main.ui b/alethzero/Main.ui
index da5ee6c4a..34f240fbf 100644
--- a/alethzero/Main.ui
+++ b/alethzero/Main.ui
@@ -208,7 +208,7 @@
    <addaction name="menu_Debug"/>
   </widget>
   <widget class="QStatusBar" name="statusbar"/>
-  <widget class="QDockWidget" name="dockWidget_2">
+  <widget class="QDockWidget" name="dockWidget_accounts">
    <property name="features">
     <set>QDockWidget::DockWidgetFeatureMask</set>
    </property>
@@ -566,7 +566,7 @@
     </layout>
    </widget>
   </widget>
-  <widget class="QDockWidget" name="dockWidget_6">
+  <widget class="QDockWidget" name="dockWidget_contracts">
    <property name="features">
     <set>QDockWidget::DockWidgetFeatureMask</set>
    </property>
diff --git a/alethzero/MainWin.cpp b/alethzero/MainWin.cpp
index d566882f3..f63cd74f0 100644
--- a/alethzero/MainWin.cpp
+++ b/alethzero/MainWin.cpp
@@ -135,6 +135,11 @@ Main::Main(QWidget *parent) :
 //		ui->log->addItem(QString::fromStdString(s));
 	};
 
+#if !ETH_FATDB
+	ui->dockWidgetAccounts->hide();
+	ui->dockWidgetContracts->hide();
+#endif
+
 #if ETH_DEBUG
 	m_servers.append("localhost:30300");
 #endif
@@ -1036,6 +1041,7 @@ void Main::refreshPending()
 
 void Main::refreshAccounts()
 {
+#if ETH_FATDB
 	cwatch << "refreshAccounts()";
 	ui->accounts->clear();
 	ui->contracts->clear();
@@ -1053,6 +1059,7 @@ void Main::refreshAccounts()
 						->setData(Qt::UserRole, QByteArray((char const*)i.data(), Address::size));
 			}
 		}
+#endif
 }
 
 void Main::refreshBlockCount()
@@ -1626,16 +1633,22 @@ void Main::on_ourAccounts_doubleClicked()
 
 void Main::on_accounts_doubleClicked()
 {
-	auto hba = ui->accounts->currentItem()->data(Qt::UserRole).toByteArray();
-	auto h = Address((byte const*)hba.data(), Address::ConstructFromPointer);
-	qApp->clipboard()->setText(QString::fromStdString(toHex(h.asArray())));
+	if (!ui->accounts->isEmpty())
+	{
+		auto hba = ui->accounts->currentItem()->data(Qt::UserRole).toByteArray();
+		auto h = Address((byte const*)hba.data(), Address::ConstructFromPointer);
+		qApp->clipboard()->setText(QString::fromStdString(toHex(h.asArray())));
+	}
 }
 
 void Main::on_contracts_doubleClicked()
 {
-	auto hba = ui->contracts->currentItem()->data(Qt::UserRole).toByteArray();
-	auto h = Address((byte const*)hba.data(), Address::ConstructFromPointer);
-	qApp->clipboard()->setText(QString::fromStdString(toHex(h.asArray())));
+	if (!ui->contracts->isEmpty())
+	{
+		auto hba = ui->contracts->currentItem()->data(Qt::UserRole).toByteArray();
+		auto h = Address((byte const*)hba.data(), Address::ConstructFromPointer);
+		qApp->clipboard()->setText(QString::fromStdString(toHex(h.asArray())));
+	}
 }
 
 static shh::FullTopic topicFromText(QString _s)
diff --git a/libethereum/Interface.h b/libethereum/Interface.h
index 68eb4b094..b78106ae1 100644
--- a/libethereum/Interface.h
+++ b/libethereum/Interface.h
@@ -138,6 +138,7 @@ public:
 	virtual StateDiff diff(unsigned _txi, BlockNumber _block) const = 0;
 
 	/// Get a list of all active addresses.
+	/// NOTE: This only works when compiled with ETH_FATDB; otherwise will throw InterfaceNotSupported.
 	virtual Addresses addresses() const { return addresses(m_default); }
 	virtual Addresses addresses(BlockNumber _block) const = 0;
 
diff --git a/libethereum/State.cpp b/libethereum/State.cpp
index c5732116d..486abde12 100644
--- a/libethereum/State.cpp
+++ b/libethereum/State.cpp
@@ -342,6 +342,7 @@ u256 State::enactOn(bytesConstRef _block, BlockInfo const& _bi, BlockChain const
 
 map<Address, u256> State::addresses() const
 {
+#if ETH_FATDB
 	map<Address, u256> ret;
 	for (auto i: m_cache)
 		if (i.second.isAlive())
@@ -350,6 +351,9 @@ map<Address, u256> State::addresses() const
 		if (m_cache.find(i.first) == m_cache.end())
 			ret[i.first] = RLP(i.second)[1].toInt<u256>();
 	return ret;
+#else
+	throw InterfaceNotSupported("State::addresses()");
+#endif
 }
 
 void State::resetCurrent()
diff --git a/libethereum/State.h b/libethereum/State.h
index 46a111a9b..3883a4897 100644
--- a/libethereum/State.h
+++ b/libethereum/State.h
@@ -127,6 +127,7 @@ public:
 	OverlayDB const& db() const { return m_db; }
 
 	/// @returns the set containing all addresses currently in use in Ethereum.
+	/// @throws InterfaceNotSupported if compiled without ETH_FATDB.
 	std::map<Address, u256> addresses() const;
 
 	/// Get the header information on the present block.