diff --git a/Applications/FileIO/CMakeLists.txt b/Applications/FileIO/CMakeLists.txt
index 06deb492e2c3d3948cfd76b08a5d489db81f3f94..71b0150b0587accaa181755ca27f002fc4d4ed61 100644
--- a/Applications/FileIO/CMakeLists.txt
+++ b/Applications/FileIO/CMakeLists.txt
@@ -2,12 +2,12 @@ GET_SOURCE_FILES(SOURCES)
 if(NOT Shapelib_FOUND)
     list(REMOVE_ITEM SOURCES SHPInterface.h SHPInterface.cpp)
 endif()
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     APPEND_SOURCE_FILES(SOURCES XmlIO/Qt)
 endif()
 APPEND_SOURCE_FILES(SOURCES Gmsh)
 
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     APPEND_SOURCE_FILES(SOURCES FEFLOW)
 endif()
 
@@ -22,7 +22,7 @@ include(${PROJECT_SOURCE_DIR}/scripts/cmake/OGSEnabledElements.cmake)
 add_library(ApplicationsFileIO ${SOURCES})
 target_link_libraries(ApplicationsFileIO DataHolderLib)
 
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     target_link_libraries(ApplicationsFileIO Qt5::Xml Qt5::XmlPatterns)
     if(WIN32 AND CMAKE_CROSSCOMPILING AND OPENSSL_FOUND)
         target_link_libraries(ApplicationsFileIO Qt5::Network ${OPENSSL_LIBRARIES} ws2_32)
diff --git a/Applications/Utils/FileConverter/CMakeLists.txt b/Applications/Utils/FileConverter/CMakeLists.txt
index 26f4b49b37b54a77420de3c7c3493d19cb63eed6..6c7d036e96b3af9383fde0182e2a7fb23f794f0a 100644
--- a/Applications/Utils/FileConverter/CMakeLists.txt
+++ b/Applications/Utils/FileConverter/CMakeLists.txt
@@ -1,15 +1,18 @@
+if (Qt5XmlPatterns_FOUND)
+    if (Shapelib_FOUND)
+        add_executable(ConvertSHPToGLI ConvertSHPToGLI.cpp)
+        set_target_properties(ConvertSHPToGLI PROPERTIES FOLDER Utilities)
+        target_link_libraries(ConvertSHPToGLI GeoLib Qt5::Xml ${Shapelib_LIBRARIES})
+    endif()
 
-if (QT4_FOUND AND Shapelib_FOUND)
-    add_executable(ConvertSHPToGLI ConvertSHPToGLI.cpp)
-    set_target_properties(ConvertSHPToGLI PROPERTIES FOLDER Utilities)
-    target_link_libraries(ConvertSHPToGLI GeoLib Qt5::Xml ${Shapelib_LIBRARIES})
-endif ()
-
-if (QT4_FOUND)
     add_executable(FEFLOW2OGS FEFLOW2OGS.cpp)
     set_target_properties(FEFLOW2OGS PROPERTIES FOLDER Utilities)
     target_link_libraries(FEFLOW2OGS ApplicationsFileIO)
     ADD_VTK_DEPENDENCY(FEFLOW2OGS)
+
+    add_executable(convertGEO convertGEO.cpp)
+    set_target_properties(convertGEO PROPERTIES FOLDER Utilities)
+    target_link_libraries(convertGEO GeoLib)
 endif ()
 
 add_executable(generateMatPropsFromMatID generateMatPropsFromMatID.cpp )
@@ -43,20 +46,18 @@ set_target_properties(TIN2VTK PROPERTIES FOLDER Utilities)
 target_link_libraries(TIN2VTK MeshLib)
 ADD_VTK_DEPENDENCY(TIN2VTK)
 
-if (QT4_FOUND)
-    add_executable(convertGEO convertGEO.cpp)
-    set_target_properties(convertGEO PROPERTIES FOLDER Utilities)
-    target_link_libraries(convertGEO GeoLib)
-endif()
-
 ####################
 ### Installation ###
 ####################
 install(TARGETS generateMatPropsFromMatID GMSH2OGS OGS2VTK VTK2OGS VTK2TIN
     RUNTIME DESTINATION bin COMPONENT ogs_converter)
 
-if(QT4_FOUND)
-    install(TARGETS ConvertSHPToGLI FEFLOW2OGS convertGEO
+if(Qt5XmlPatterns_FOUND)
+    if(Shapelib_FOUND)
+        install(TARGETS ConvertSHPToGLI
+            RUNTIME DESTINATION bin COMPONENT ogs_converter)
+    endif()
+    install(TARGETS  FEFLOW2OGS convertGEO
         RUNTIME DESTINATION bin COMPONENT ogs_converter)
 endif()
 
diff --git a/Applications/Utils/GeoTools/CMakeLists.txt b/Applications/Utils/GeoTools/CMakeLists.txt
index 8144402f4494add9729445d0544b621065596639..82cbb066974e94c626a3ced9d527b6cfc4e43502 100644
--- a/Applications/Utils/GeoTools/CMakeLists.txt
+++ b/Applications/Utils/GeoTools/CMakeLists.txt
@@ -1,4 +1,4 @@
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     add_executable(TriangulatePolyline TriangulatePolyline.cpp)
     target_link_libraries(TriangulatePolyline GeoLib)
     set_target_properties(TriangulatePolyline PROPERTIES FOLDER Utilities)
@@ -16,4 +16,4 @@ if(QT4_FOUND)
         RUNTIME DESTINATION bin
         COMPONENT Utilities
     )
-endif() # QT4_FOUND
+endif()
diff --git a/BaseLib/CMakeLists.txt b/BaseLib/CMakeLists.txt
index f616e2820935a34be08b9c6e1572244d01dd9fbf..f1ffd71688d5cdfe6150bf7ae2d01d8a6cde34f6 100644
--- a/BaseLib/CMakeLists.txt
+++ b/BaseLib/CMakeLists.txt
@@ -3,7 +3,7 @@ APPEND_SOURCE_FILES(SOURCES IO)
 
 APPEND_SOURCE_FILES(SOURCES IO/XmlIO)
 
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     APPEND_SOURCE_FILES(SOURCES IO/XmlIO/Qt)
 endif()
 
@@ -22,7 +22,7 @@ if(MSVC)
     target_link_libraries(BaseLib WinMM) # needed for timeGetTime
 endif()
 
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     target_link_libraries(BaseLib Qt5::Xml Qt5::XmlPatterns)
     if(WIN32 AND CMAKE_CROSSCOMPILING AND OPENSSL_FOUND)
         target_link_libraries(BaseLib Qt5::Network ${OPENSSL_LIBRARIES} ws2_32)
diff --git a/GeoLib/CMakeLists.txt b/GeoLib/CMakeLists.txt
index 87187d88fafcd8ae72501b3ad5feed13bd11d312..fdf788ef33cb74780fa4d4ed0c04fe578bcae096 100644
--- a/GeoLib/CMakeLists.txt
+++ b/GeoLib/CMakeLists.txt
@@ -7,7 +7,7 @@ APPEND_SOURCE_FILES(SOURCES IO/Legacy)
 APPEND_SOURCE_FILES(SOURCES IO/XmlIO/Rapid)
 APPEND_SOURCE_FILES(SOURCES IO/XmlIO/Boost)
 
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     APPEND_SOURCE_FILES(SOURCES IO/XmlIO/Qt)
 endif()
 
@@ -20,7 +20,7 @@ target_link_libraries(GeoLib
     MathLib
 )
 
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     target_link_libraries(GeoLib Qt5::Xml Qt5::XmlPatterns)
     if(WIN32 AND CMAKE_CROSSCOMPILING AND OPENSSL_FOUND)
         target_link_libraries(GeoLib Qt5::Network ${OPENSSL_LIBRARIES} ws2_32)
diff --git a/Tests/CMakeLists.txt b/Tests/CMakeLists.txt
index 5c7c197f13e9b7783c14ef7dad3497a81b1ca89c..b98f1586537f587cde6abd925e90a3a8a239354b 100644
--- a/Tests/CMakeLists.txt
+++ b/Tests/CMakeLists.txt
@@ -20,7 +20,7 @@ APPEND_SOURCE_FILES(TEST_SOURCES NumLib)
 APPEND_SOURCE_FILES(TEST_SOURCES ProcessLib)
 APPEND_SOURCE_FILES(TEST_SOURCES ProcessLib/LiquidFlow)
 
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     APPEND_SOURCE_FILES(TEST_SOURCES FileIO_Qt)
 endif()
 
@@ -68,7 +68,7 @@ if(OGS_BUILD_SWMM)
     target_link_libraries(testrunner SwmmInterface)
 endif()
 
-if(QT4_FOUND)
+if(Qt5XmlPatterns_FOUND)
     target_link_libraries(testrunner Qt5::Core Qt5::Gui Qt5::Xml Qt5::Network)
     if(CMAKE_CROSSCOMPILING)
         target_link_libraries(testrunner