diff --git a/devel/kchmviewer/Portfile b/devel/kchmviewer/Portfile
index c5df7cbb9a34d..be22d0617864f 100644
--- a/devel/kchmviewer/Portfile
+++ b/devel/kchmviewer/Portfile
@@ -2,10 +2,6 @@
 
 PortSystem          1.0
 
-# kchmviewer's KDE variant still requires KDE4 and will thus not be shipped for now.
-# The pure Qt variant is obtained by using QMake instead of CMake.
-PortGroup           qmake5 1.0
-
 name                kchmviewer
 version             7.7
 revision            1
@@ -26,7 +22,23 @@ distname            ${name}-${version}
 master_sites        sourceforge:project/${name}/${name}/${version}
 
 checksums           rmd160  3b072a3225c5a4c796a9406232c3f696285d9aa4 \
-                    sha256  27cbac45c786b1718550a87e6f86010e161302b426c6396ff2a3091b913b17dd
+                    sha256  27cbac45c786b1718550a87e6f86010e161302b426c6396ff2a3091b913b17dd \
+                    size    345952
+
+# kchmviewer's KDE variant still requires KDE4 and will thus not be shipped for now.
+# The pure Qt variant is obtained by using QMake instead of CMake.
+if {${os.platform} ne "darwin" || ${os.major} > 11} {
+    PortGroup       qmake5 1.0
+
+    # kchmviewer is transitioning to QtWebEngine, but that adaptation is not yet functional.
+    # (and WebKit is a much more appropriate choice anyway.)
+    qt5.depends_component \
+                    qtwebkit
+} else {
+    # Fallback for older systems without Qt5:
+    PortGroup       qmake 1.0
+
+}
 
 depends_build-append \
                     port:dos2unix
@@ -34,11 +46,6 @@ depends_build-append \
 depends_lib-append  port:libzip \
                     port:chmlib
 
-# kchmviewer is transitioning to QtWebEngine, but that adaptation is not yet functional.
-# (and WebKit is a much more appropriate choice anyway.)
-qt5.depends_component \
-                    qtwebkit
-
 post-extract {
     # force consistent line-endings
     system -W ${worksrcpath} "find . \\\( -name \"*.cpp\" -o -name \"*.h\" -o -name \"*.pro\" \\\) -exec dos2unix '{}' \";\""
@@ -62,6 +69,9 @@ post-patch {
                     ${worksrcpath}/src/src.pro
 }
 
+# zip.h: error: wrong number of arguments specified for ‘deprecated’ attribute
+compiler.blacklist-append   *gcc-4.0 *gcc-4.2
+
 configure.cppflags-append   -I${prefix}/lib/libzip/include
 configure.pre_args-append   ${worksrcpath}/${name}.pro
 configure.args-append       -recursive