diff --git a/kcms/colors/CMakeLists.txt b/kcms/colors/CMakeLists.txt
--- a/kcms/colors/CMakeLists.txt
+++ b/kcms/colors/CMakeLists.txt
@@ -36,6 +36,7 @@
     KF5::KIOCore
     KF5::CoreAddons
     KF5::NewStuff
+    KF5::WindowSystem
     )
 if(X11_FOUND)
     target_link_libraries(kcolorschemeeditor ${X11_LIBRARIES} Qt5::X11Extras)
@@ -76,7 +77,8 @@
     KF5::KIOCore
     KF5::CoreAddons
     Qt5::DBus
-    KF5::NewStuff)
+    KF5::NewStuff
+    KF5::WindowSystem)
 
 if(X11_FOUND)
     target_link_libraries(kcm_colors ${X11_LIBRARIES} Qt5::X11Extras)
diff --git a/kcms/krdb/krdb.cpp b/kcms/krdb/krdb.cpp
--- a/kcms/krdb/krdb.cpp
+++ b/kcms/krdb/krdb.cpp
@@ -44,6 +44,7 @@
 #include <kprocess.h>
 #include <KLocalizedString>
 #include <kdelibs4migration.h>
+#include <KWindowSystem>
 
 #include "krdb.h"
 #if HAVE_X11
@@ -534,8 +535,17 @@
     KConfig _cfgfonts( QStringLiteral("kcmfonts") );
     KConfigGroup cfgfonts(&_cfgfonts, "General");
 
-    if( cfgfonts.readEntry( "forceFontDPI", 0 ) != 0 )
-      contents += "Xft.dpi: " + cfgfonts.readEntry( "forceFontDPI" ) + '\n';
+    int dpi;
+
+    //even though this sets up the X rdb, we want to use the value the
+    //user has set to use when under wayland - as X apps will be scaled by the compositor
+    if (KWindowSystem::isPlatformWayland()) {
+        dpi = cfgfonts.readEntry( "forceFontDPIWayland", 0);
+    } else {
+        dpi = cfgfonts.readEntry( "forceFontDPI", 0);
+    }
+    if( dpi != 0 )
+      contents += "Xft.dpi: " + QString::number(dpi) + '\n';
     else
     {
       KProcess proc;