diff --git a/CHANGES b/CHANGES
index dfbff119b8e5..42212fb9d3d8 100644
--- a/CHANGES
+++ b/CHANGES
@@ -10,6 +10,23 @@ in the release notes and/or placed into UPDATING.
 
 All ports committers are allowed to commit to this file.
 
+20220XXX:
+AUTHOR: zirias@FreeBSD.org
+
+  kde.mk, qt.mk and pyqt.mk now use a colon for component suffixes
+
+  Suffixes for build, run and test (for pyqt) dependencies used an underscore
+  previously. This was not in line with most other USES, using a colon for
+  that purpose.
+
+  So if you previously had for example
+
+	USE_QT=	buildtools_build
+
+  replace it with
+
+	USE_QT= buildtools:build
+
 20220826:
 AUTHOR: tcberner@FreeBSD.org
 
diff --git a/Mk/Uses/kde.mk b/Mk/Uses/kde.mk
index 7014f4de20e9..7a977638fdf4 100644
--- a/Mk/Uses/kde.mk
+++ b/Mk/Uses/kde.mk
@@ -9,8 +9,8 @@
 #
 # USE_KDE	List of KF5/Plasma5 components (other ports) that this
 #		port depends on.
-#		* foo_build	Add a build-time dependency (BUILD_DEPENDS)
-#		* foo_run	Add a run-time dependency (RUN_DEPENDS)
+#		* foo:build	Add a build-time dependency (BUILD_DEPENDS)
+#		* foo:run	Add a run-time dependency (RUN_DEPENDS)
 #		* foo (default)	Add both dependencies on component <foo>, or
 #				a LIB_DEPENDS if applicable.
 #
@@ -25,7 +25,7 @@
 #
 # option DOCS	If the port is part of kde-applications (see CATEGORIES,
 #		above) and has an option defined for DOCS then a dependency
-#		for doctools_build is added. The option itself doesn't
+#		for doctools:build is added. The option itself doesn't
 #		have to do anything -- the dependency is always there.
 #
 # KDE_INVENT	If the port does not have a regular release, and should
@@ -159,7 +159,7 @@ _KDE_OPTIONS=		bogus ${OPTIONS_DEFINE}
 .        if ${_KDE_OPTIONS:MDOCS}
 DOCSDIR=		${PREFIX}/share/doc
 PORTDOCS?=		HTML/*
-USE_KDE+=		doctools_build
+USE_KDE+=		doctools:build
 .        endif
 # Further pass along a SHLIB_VER PLIST_SUB
 PLIST_SUB+=		KDE_APPLICATIONS_SHLIB_VER=${KDE_APPLICATIONS_SHLIB_VER} \
@@ -869,18 +869,18 @@ kde-${comp}_PATH=		${kde-${comp}${_KDE_VERSION}_LIB}
 _USE_KDE_ALL=	${_USE_${_KDE_RELNAME}_ALL}
 
 # Iterate through components deprived of suffix.
-.    for component in ${USE_KDE:O:u:C/_.+//}
+.    for component in ${USE_KDE:O:u:C/:.+//}
   # Check that the component is valid.
 .      if ${_USE_KDE_ALL:M${component}} != ""
    # Skip meta-components (currently none).
 .        if defined(kde-${component}_PORT) && (defined(kde-${component}_PATH) || defined(kde-${component}_LIB))
     # Check if a dependency type is explicitly requested.
-.          if ${USE_KDE:M${component}_*} != "" && ${USE_KDE:M${component}} == ""
+.          if ${USE_KDE:M${component}\:*} != "" && ${USE_KDE:M${component}} == ""
 kde-${component}_TYPE=	# empty
-.            if ${USE_KDE:M${component}_build} != ""
+.            if ${USE_KDE:M${component}\:build} != ""
 kde-${component}_TYPE+=	build
 .            endif
-.            if ${USE_KDE:M${component}_run} != ""
+.            if ${USE_KDE:M${component}\:run} != ""
 kde-${component}_TYPE+=	run
 .            endif
 .          endif # ${USE_KDE:M${component}_*} != "" && ${USE_KDE:M${component}} == ""
diff --git a/Mk/Uses/pyqt.mk b/Mk/Uses/pyqt.mk
index a421a438056b..33ce894a4f04 100644
--- a/Mk/Uses/pyqt.mk
+++ b/Mk/Uses/pyqt.mk
@@ -11,10 +11,10 @@
 #		targets are then set assuming a certain tarball and
 #		port layout.
 # USE_PYQT	- List of PyQt components to depend on
-#		* foo_build    only build depend
-#		* foo_run      only run depend
-#		* foo_test     only test depend
-#		* foo          both (default)
+#		* foo:build    only build depend
+#		* foo:run      only run depend
+#		* foo:test     only test depend
+#		* foo          build and run depend (default)
 # PYQT_SIPDIR	- where sip files will be installed to
 # PYQT_APIDIR	- where api files will be installed to
 # PYQT_DOCDIR	- where doc files will be installed to
@@ -199,7 +199,7 @@ _USE_PYQT_ALL+=				${_USE_SIP_ALL} \
 					${_USE_QSCINTILLA} \
 					${_USE_PYQTBUILDER}
 .  for comp in ${_USE_PYQT_ALL:O:u}
-_USE_PYQT_ALL_SUFFIXED+=		py-${comp} py-${comp}_build py-${comp}_run py-${comp}_test
+_USE_PYQT_ALL_SUFFIXED+=		py-${comp} py-${comp}:build py-${comp}:run py-${comp}:test
 py-${comp}_BUILD_DEPENDS?=		${py-${comp}_PATH}:${py-${comp}_PORT}@${PY_FLAVOR}
 py-${comp}_RUN_DEPENDS?=		${py-${comp}_PATH}:${py-${comp}_PORT}@${PY_FLAVOR}
 py-${comp}_TEST_DEPENDS?=		${py-${comp}_PATH}:${py-${comp}_PORT}@${PY_FLAVOR}
@@ -211,9 +211,9 @@ py-${comp}_test_TEST_DEPENDS?=		${py-${comp}_TEST_DEPENDS}
 _USE_PYQT=      ${USE_PYQT:O:u}
 .  for comp in ${_USE_PYQT}
 .    if ${_USE_PYQT_ALL_SUFFIXED:Mpy-${comp}}
-BUILD_DEPENDS+=		${py-${comp}_BUILD_DEPENDS}
-RUN_DEPENDS+=		${py-${comp}_RUN_DEPENDS}
-TEST_DEPENDS+=		${py-${comp}_TEST_DEPENDS}
+BUILD_DEPENDS+=		${py-${comp:S/:/_/}_BUILD_DEPENDS}
+RUN_DEPENDS+=		${py-${comp:S/:/_/}_RUN_DEPENDS}
+TEST_DEPENDS+=		${py-${comp:S/:/_/}_TEST_DEPENDS}
 .    else
 IGNORE?=	cannot be installed: unknown USE_PYQT component ${comp} #'
 .    endif
diff --git a/Mk/Uses/qmake.mk b/Mk/Uses/qmake.mk
index 48304c742493..e6fc0758026a 100644
--- a/Mk/Uses/qmake.mk
+++ b/Mk/Uses/qmake.mk
@@ -110,7 +110,7 @@ QMAKE_SOURCE_PATH?=	# empty
 
 # Add qmake to USE_QT -- unless it's qmake itself
 .  if !${PORTNAME} == qmake && ${_QT_VER:M5}
-USE_QT+=		qmake_build
+USE_QT+=		qmake:build
 .  endif
 
 .  if empty(qmake_ARGS:Mno_env)
diff --git a/Mk/Uses/qt.mk b/Mk/Uses/qt.mk
index 98c60ae1e2f2..87f864309aef 100644
--- a/Mk/Uses/qt.mk
+++ b/Mk/Uses/qt.mk
@@ -11,8 +11,8 @@
 #   Versions:		5
 #
 # Port variables:
-# USE_QT		- List of Qt modules to depend on, with optional '_build'
-#			  and '_run' suffixes. Define it empty to include this file
+# USE_QT		- List of Qt modules to depend on, with optional ':build'
+#			  and ':run' suffixes. Define it empty to include this file
 #			  without depending on Qt ports.
 #
 # MAINTAINER:	kde@FreeBSD.org
@@ -399,18 +399,18 @@ _USE_QT_ALL=		${_USE_QT_COMMON} \
 			${_USE_QT${_QT_VER}_ONLY}
 _USE_QT=		${USE_QT}
 # Iterate through components deprived of suffix.
-.  for component in ${_USE_QT:O:u:C/_(build|run)$//}
+.  for component in ${_USE_QT:O:u:C/:(build|run)$//}
 # Check that the component is valid.
 .    if ${_USE_QT_ALL:M${component}} != ""
 # Skip meta-components (currently none).
 .      if defined(qt-${component}_PORT) && (defined(qt-${component}_PATH) || defined(qt-${component}_LIB))
 # Check if a dependency type is explicitly requested.
-.        if ${_USE_QT:M${component}_*} != "" && ${_USE_QT:M${component}} == ""
+.        if ${_USE_QT:M${component}\:*} != "" && ${_USE_QT:M${component}} == ""
 qt-${component}_TYPE=		# empty
-.          if ${_USE_QT:M${component}_build} != ""
+.          if ${_USE_QT:M${component}\:build} != ""
 qt-${component}_TYPE+=		build
 .          endif
-.          if ${_USE_QT:M${component}_run} != ""
+.          if ${_USE_QT:M${component}\:run} != ""
 qt-${component}_TYPE+=		run
 .          endif
 .        endif # ${_USE_QT:M${component}_*} != "" && ${_USE_QT:M${component}} == ""