diff --git a/eclass/ruby-single.eclass b/eclass/ruby-single.eclass
index f8ef648a16f8..5b8f01d63c4f 100644
--- a/eclass/ruby-single.eclass
+++ b/eclass/ruby-single.eclass
@@ -70,14 +70,33 @@ inherit ruby-utils
 # The order of dependencies will change over time to best match the
 # current state of ruby targets, e.g. stable version first.
 
+
+# @FUNCTION: ruby_single_implementation_command
+# @RETURN: the path to the preferred Ruby implementation
+# @DESCRIPTION:
+# Returns the path of the first Ruby implementation from
+# RUBY_TARGETS_PREFERENCE that is both installed and in USE_RUBY.
+ruby_single_implementation_command() {
+	local _ruby_name
+
+	for _ruby_name in ${RUBY_TARGETS_PREFERENCE}; do
+		if has ${_ruby_name} ${USE_RUBY} && has_version "virtual/rubygems[ruby_targets_${_ruby_name}]"; then
+			type -P ${_ruby_name} 2>/dev/null && return 0
+		fi
+	done
+
+	die "Unable to find working Ruby implementation"
+}
+
+
 _ruby_single_implementations_depend() {
 	local depend
 	for _ruby_implementation in ${RUBY_TARGETS_PREFERENCE}; do
-		if [[ ${USE_RUBY} =~ ${_ruby_implementation} ]]; then
-			depend="${depend} $(_ruby_implementation_depend $_ruby_implementation)"
+		if has ${_ruby_implementation} ${USE_RUBY}; then
+			depend+=" virtual/rubygems[ruby_targets_${_ruby_implementation}]"
 		fi
 	done
-	echo "|| ( ${depend} ) virtual/rubygems"
+	echo "|| ( ${depend} )"
 }
 
 _ruby_single_set_globals() {
diff --git a/net-libs/webkit-gtk/webkit-gtk-2.14.3.ebuild b/net-libs/webkit-gtk/webkit-gtk-2.14.3.ebuild
index 3e18145454f4..5885c941fbcd 100644
--- a/net-libs/webkit-gtk/webkit-gtk-2.14.3.ebuild
+++ b/net-libs/webkit-gtk/webkit-gtk-2.14.3.ebuild
@@ -196,18 +196,6 @@ src_configure() {
 	# Multiple rendering bugs on youtube, github, etc without this, bug #547224
 	append-flags $(test-flags -fno-strict-aliasing)
 
-	local ruby_interpreter=""
-
-	if has_version "virtual/rubygems[ruby_targets_ruby24]"; then
-		ruby_interpreter="-DRUBY_EXECUTABLE=$(type -P ruby24)"
-	elif has_version "virtual/rubygems[ruby_targets_ruby23]"; then
-		ruby_interpreter="-DRUBY_EXECUTABLE=$(type -P ruby23)"
-	elif has_version "virtual/rubygems[ruby_targets_ruby22]"; then
-		ruby_interpreter="-DRUBY_EXECUTABLE=$(type -P ruby22)"
-	else
-		ruby_interpreter="-DRUBY_EXECUTABLE=$(type -P ruby21)"
-	fi
-
 	# TODO: Check Web Audio support
 	# should somehow let user select between them?
 	#
@@ -254,7 +242,7 @@ src_configure() {
 		-DENABLE_ACCELERATED_2D_CANVAS=${canvas_enabled}
 		-DCMAKE_BUILD_TYPE=Release
 		-DPORT=GTK
-		${ruby_interpreter}
+		-DRUBY_EXECUTABLE="$(ruby_single_implementation_command)"
 	)
 
 	# Allow it to use GOLD when possible as it has all the magic to
diff --git a/net-libs/webkit-gtk/webkit-gtk-2.4.11-r1.ebuild b/net-libs/webkit-gtk/webkit-gtk-2.4.11-r1.ebuild
index 4ea44042ecd9..852e8e80cab9 100644
--- a/net-libs/webkit-gtk/webkit-gtk-2.4.11-r1.ebuild
+++ b/net-libs/webkit-gtk/webkit-gtk-2.4.11-r1.ebuild
@@ -4,7 +4,7 @@
 
 EAPI="6"
 PYTHON_COMPAT=( python2_7 )
-USE_RUBY="ruby20 ruby21 ruby22 ruby23"
+USE_RUBY="ruby20 ruby21 ruby22 ruby23 ruby24"
 
 inherit autotools check-reqs flag-o-matic gnome2 pax-utils python-any-r1 ruby-single toolchain-funcs versionator virtualx
 
@@ -207,18 +207,6 @@ src_configure() {
 		append-ldflags "-Wl,--reduce-memory-overheads"
 	fi
 
-	local ruby_interpreter=""
-
-	if has_version "virtual/rubygems[ruby_targets_ruby23]"; then
-		ruby_interpreter="RUBY=$(type -P ruby23)"
-	elif has_version "virtual/rubygems[ruby_targets_ruby22]"; then
-		ruby_interpreter="RUBY=$(type -P ruby22)"
-	elif has_version "virtual/rubygems[ruby_targets_ruby21]"; then
-		ruby_interpreter="RUBY=$(type -P ruby21)"
-	else
-		ruby_interpreter="RUBY=$(type -P ruby20)"
-	fi
-
 	# TODO: Check Web Audio support
 	# should somehow let user select between them?
 	#
@@ -245,7 +233,7 @@ src_configure() {
 		--with-gtk=3.0 \
 		--enable-dependency-tracking \
 		--disable-gtk-doc \
-		${ruby_interpreter}
+		RUBY="$(ruby_single_implementation_command)"
 }
 
 src_test() {
diff --git a/net-libs/webkit-gtk/webkit-gtk-2.4.11-r200.ebuild b/net-libs/webkit-gtk/webkit-gtk-2.4.11-r200.ebuild
index a92c6b1baa43..3d510eb10654 100644
--- a/net-libs/webkit-gtk/webkit-gtk-2.4.11-r200.ebuild
+++ b/net-libs/webkit-gtk/webkit-gtk-2.4.11-r200.ebuild
@@ -4,7 +4,7 @@
 
 EAPI="6"
 PYTHON_COMPAT=( python2_7 )
-USE_RUBY="ruby20 ruby21 ruby22 ruby23"
+USE_RUBY="ruby20 ruby21 ruby22 ruby23 ruby24"
 
 inherit autotools check-reqs flag-o-matic gnome2 pax-utils python-any-r1 ruby-single toolchain-funcs versionator virtualx
 
@@ -192,18 +192,6 @@ src_configure() {
 		append-ldflags "-Wl,--reduce-memory-overheads"
 	fi
 
-	local ruby_interpreter=""
-
-	if has_version "virtual/rubygems[ruby_targets_ruby23]"; then
-		ruby_interpreter="RUBY=$(type -P ruby23)"
-	elif has_version "virtual/rubygems[ruby_targets_ruby22]"; then
-		ruby_interpreter="RUBY=$(type -P ruby22)"
-	elif has_version "virtual/rubygems[ruby_targets_ruby21]"; then
-		ruby_interpreter="RUBY=$(type -P ruby21)"
-	else
-		ruby_interpreter="RUBY=$(type -P ruby20)"
-	fi
-
 	# TODO: Check Web Audio support
 	# should somehow let user select between them?
 	#
@@ -229,7 +217,7 @@ src_configure() {
 		--disable-webkit2 \
 		--enable-dependency-tracking \
 		--disable-gtk-doc \
-		${ruby_interpreter}
+		RUBY="$(ruby_single_implementation_command)"
 }
 
 src_test() {