diff --git a/appveyor-dpkg.sh b/appveyor-dpkg.sh
index 8df8b79..82af7c8 100755
--- a/appveyor-dpkg.sh
+++ b/appveyor-dpkg.sh
@@ -13,4 +13,5 @@ apt-get -y install \
 	\
 	qtbase5-dev \
 	qttools5-dev \
-	qttools5-dev-tools
+	qttools5-dev-tools \
+	libkf5widgetsaddons-dev
diff --git a/cmake/libs/CheckNettle2or3.cmake b/cmake/libs/CheckNettle2or3.cmake
index bb17a52..b1514a4 100644
--- a/cmake/libs/CheckNettle2or3.cmake
+++ b/cmake/libs/CheckNettle2or3.cmake
@@ -6,6 +6,7 @@ FUNCTION(CHECK_NETTLE_2_OR_3)
 	FIND_PACKAGE(NETTLE)
 	SET(HAVE_NETTLE ${NETTLE_FOUND})
 	SET(HAVE_NETTLE ${NETTLE_FOUND} PARENT_SCOPE)
+	SET(NETTLE_FOUND ${NETTLE_FOUND} PARENT_SCOPE)
 	IF(HAVE_NETTLE)
 		# Check if this is Nettle 3.x.
 		# Nettle 3.1 added version.h, which isn't available
diff --git a/src/qrvthtool/CMakeLists.txt b/src/qrvthtool/CMakeLists.txt
index aa45c2f..d2649a5 100644
--- a/src/qrvthtool/CMakeLists.txt
+++ b/src/qrvthtool/CMakeLists.txt
@@ -92,10 +92,10 @@ ELSE()
         SET(QRVTHTOOL_TRANSLATIONS_DIRECTORY "${CMAKE_INSTALL_PREFIX}/${DIR_INSTALL_TRANSLATIONS}")
 ENDIF()
 
-# KDE5: Check for KWidgetsAddons headers for notification sounds.
+# KF5/KF6: Check for KWidgetsAddons headers for notification sounds.
 IF(UNIX AND NOT APPLE)
 	# Reference: http://www.proli.net/2014/06/21/porting-your-project-to-qt5kf5/
-	# Find KDE5 Extra CMake Modules.
+	# Find KF5/KF6 Extra CMake Modules.
 	FIND_PACKAGE(ECM ${ECM_MINIMUM_VERSION} NO_MODULE)
 	IF(ECM_MODULE_PATH AND ECM_KDE_MODULE_DIR)
 		# Make sure ECM's CMake files don't create an uninstall rule.
@@ -104,7 +104,7 @@ IF(UNIX AND NOT APPLE)
 		# Don't add KDE tests to the CTest build.
 		SET(KDE_SKIP_TEST_SETTINGS TRUE)
 
-		# Include KDE5 CMake modules.
+		# Include KF5/KF6 CMake modules.
 		LIST(APPEND CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${ECM_KDE_MODULE_DIR})
 		# NOTE: The following are not needed for rvthtool and cause
 		# duplicate moc generation, but we're leaving it here for reference.
@@ -116,7 +116,7 @@ IF(UNIX AND NOT APPLE)
 		# NOTE: Not needed because KDECompilerSettings isn't used.
 		#STRING(REPLACE "-std=iso9899:1990" "" CMAKE_C_FLAGS "${CMAKE_C_FLAGS}")
 
-		# Find KDE5. (TODO: Version?)
+		# Find KF5/KF6. (TODO: Version?)
 		FIND_PACKAGE(${KF_NS} ${KF_MIN} COMPONENTS WidgetsAddons)
 		IF(${KF_NS}WidgetsAddons_FOUND)
 			SET(HAVE_KF_WidgetsAddons 1)