diff --git a/src/ShellCheck/Analytics.hs b/src/ShellCheck/Analytics.hs
index e6479f3..a1d4b2e 100644
--- a/src/ShellCheck/Analytics.hs
+++ b/src/ShellCheck/Analytics.hs
@@ -831,6 +831,10 @@ checkArrayAsString _ (T_Assignment id _ _ _ word) =
           "Brace expansions and globs are literal in assignments. Quote it or use an array."
 checkArrayAsString _ _ = return ()
 
+arrayVariables params =
+    shellArrayVariables ++
+    if isPortageBuild params then shellArrayVariables else []
+
 prop_checkArrayWithoutIndex1 = verifyTree checkArrayWithoutIndex "foo=(a b); echo $foo"
 prop_checkArrayWithoutIndex2 = verifyNotTree checkArrayWithoutIndex "foo='bar baz'; foo=($foo); echo ${foo[0]}"
 prop_checkArrayWithoutIndex3 = verifyTree checkArrayWithoutIndex "coproc foo while true; do echo cow; done; echo $foo"
@@ -844,7 +848,7 @@ prop_checkArrayWithoutIndex10= verifyTree checkArrayWithoutIndex "read -ra arr <
 checkArrayWithoutIndex params _ =
     doVariableFlowAnalysis readF writeF defaultMap (variableFlow params)
   where
-    defaultMap = Map.fromList $ map (\x -> (x,())) arrayVariables
+    defaultMap = Map.fromList $ map (\x -> (x,())) (arrayVariables params)
     readF _ (T_DollarBraced id _ token) _ = do
         map <- get
         return . maybeToList $ do
@@ -1813,6 +1817,10 @@ checkSpacefulness params = checkSpacefulness' onFind params
             && isParamTo parents ":" token
 
 
+variablesWithoutSpaces params =
+    shellVariablesWithoutSpaces ++
+    if isPortageBuild params then portageVariablesWithoutSpaces else []
+
 prop_checkSpacefulness4v= verifyTree checkVerboseSpacefulness "foo=3; foo=$(echo $foo)"
 prop_checkSpacefulness8v= verifyTree checkVerboseSpacefulness "a=foo\\ bar; a=foo; rm $a"
 prop_checkSpacefulness28v = verifyTree checkVerboseSpacefulness "exec {n}>&1; echo $n"
@@ -1832,7 +1840,7 @@ checkSpacefulness'
 checkSpacefulness' onFind params t =
     doVariableFlowAnalysis readF writeF (Map.fromList defaults) (variableFlow params)
   where
-    defaults = zip variablesWithoutSpaces (repeat False)
+    defaults = zip (variablesWithoutSpaces params) (repeat False)
 
     hasSpaces name = gets (Map.findWithDefault True name)
 
@@ -2044,6 +2052,11 @@ checkFunctionsUsedExternally params t =
             info definitionId 2032 $
               "Use own script or sh -c '..' to run this from " ++ cmd ++ "."
 
+internalVariables params =
+    genericInternalVariables ++
+    if shellType params == Ksh then kshInternalVariables else [] ++
+    if isPortageBuild params then portageInternalVariables else []
+
 prop_checkUnused0 = verifyNotTree checkUnusedAssignments "var=foo; echo $var"
 prop_checkUnused1 = verifyTree checkUnusedAssignments "var=foo; echo $bar"
 prop_checkUnused2 = verifyNotTree checkUnusedAssignments "var=foo; export var;"
@@ -2111,7 +2124,7 @@ checkUnusedAssignments params t = execWriter (mapM_ warnFor unused)
             name ++ " appears unused. Verify use (or export if used externally)."
 
     stripSuffix = takeWhile isVariableChar
-    defaultMap = Map.fromList $ zip internalVariables $ repeat ()
+    defaultMap = Map.fromList $ zip (internalVariables params) $ repeat ()
 
 prop_checkUnassignedReferences1 = verifyTree checkUnassignedReferences "echo $foo"
 prop_checkUnassignedReferences2 = verifyNotTree checkUnassignedReferences "foo=hello; echo $foo"
@@ -2156,7 +2169,7 @@ checkUnassignedReferences = checkUnassignedReferences' False
 checkUnassignedReferences' includeGlobals params t = warnings
   where
     (readMap, writeMap) = execState (mapM tally $ variableFlow params) (Map.empty, Map.empty)
-    defaultAssigned = Map.fromList $ map (\a -> (a, ())) $ filter (not . null) internalVariables
+    defaultAssigned = Map.fromList $ map (\a -> (a, ())) $ filter (not . null) (internalVariables params)
 
     tally (Assignment (_, _, name, _))  =
         modify (\(read, written) -> (read, Map.insert name () written))
@@ -3095,7 +3108,7 @@ checkSplittingInArrays params t =
         T_DollarBraced id _ str |
             not (isCountingReference part)
             && not (isQuotedAlternativeReference part)
-            && not (getBracedReference (bracedString part) `elem` variablesWithoutSpaces)
+            && not (getBracedReference (bracedString part) `elem` (variablesWithoutSpaces params))
             -> warn id 2206 $
                 if shellType params == Ksh
                 then "Quote to prevent word splitting/globbing, or split robustly with read -A or while read."
diff --git a/src/ShellCheck/Data.hs b/src/ShellCheck/Data.hs
index 1394c04..91146c8 100644
--- a/src/ShellCheck/Data.hs
+++ b/src/ShellCheck/Data.hs
@@ -6,7 +6,7 @@ import Paths_ShellCheck (version)
 
 shellcheckVersion = showVersion version
 
-internalVariables = [
+genericInternalVariables = [
     -- Generic
     "", "_", "rest", "REST",
 
@@ -34,19 +34,34 @@ internalVariables = [
     "USER", "TZ", "TERM", "LOGNAME", "LD_LIBRARY_PATH", "LANGUAGE", "DISPLAY",
     "HOSTNAME", "KRB5CCNAME", "XAUTHORITY"
 
-    -- Ksh
-    , ".sh.version"
-
     -- shflags
     , "FLAGS_ARGC", "FLAGS_ARGV", "FLAGS_ERROR", "FLAGS_FALSE", "FLAGS_HELP",
     "FLAGS_PARENT", "FLAGS_RESERVED", "FLAGS_TRUE", "FLAGS_VERSION",
     "flags_error", "flags_return"
   ]
 
+kshInternalVariables = [
+    ".sh.version"
+  ]
+
+portageInternalVariables = [
+    "A", "BDEPEND", "BROOT", "CATEGORY", "D", "DEPEND", "DESCRIPTION",
+    "DISTDIR", "DOCS", "EAPI", "ED", "EPREFIX", "EROOT", "ESYSROOT", "FILESDIR",
+    "HOME", "HOMEPAGE", "HTML_DOCS", "IUSE", "KEYWORDS", "LICENSE", "P",
+    "PATCHES", "PDEPEND", "PF", "PN", "PR", "PROPERTIES", "PV", "PVR",
+    "QA_AM_MAINTAINER_MODE", "QA_CONFIGURE_OPTIONS", "QA_DESKTOP_FILE",
+    "QA_DT_NEEDED", "QA_EXECSTACK", "QA_FLAGS_IGNORED", "QA_MULTILIB_PATHS",
+    "QA_PREBUILT", "QA_PRESTRIPPED", "QA_SONAME", "QA_SONAME_NO_SYMLINK",
+    "QA_TEXTRELS", "QA_WX_LOAD", "RDEPEND", "REQUIRED_USE", "RESTRICT", "ROOT",
+    "S", "SLOT", "SRC_TEST", "SRC_URI", "STRIP_MASK", "SUBSLOT", "SYSROOT",
+    "T", "WORKDIR"
+  ]
+
 specialVariablesWithoutSpaces = [
     "$", "-", "?", "!", "#"
   ]
-variablesWithoutSpaces = specialVariablesWithoutSpaces ++ [
+
+shellVariablesWithoutSpaces = specialVariablesWithoutSpaces ++ [
     "BASHPID", "BASH_ARGC", "BASH_LINENO", "BASH_SUBSHELL", "EUID", "LINENO",
     "OPTIND", "PPID", "RANDOM", "SECONDS", "SHELLOPTS", "SHLVL", "UID",
     "COLUMNS", "HISTFILESIZE", "HISTSIZE", "LINES"
@@ -55,18 +70,26 @@ variablesWithoutSpaces = specialVariablesWithoutSpaces ++ [
     , "FLAGS_ERROR", "FLAGS_FALSE", "FLAGS_TRUE"
   ]
 
+portageVariablesWithoutSpaces = [
+    "EAPI", "P", "PF", "PN", "PR", "PV", "PVR", "SLOT"
+  ]
+
 specialVariables = specialVariablesWithoutSpaces ++ ["@", "*"]
 
 unbracedVariables = specialVariables ++ [
     "0", "1", "2", "3", "4", "5", "6", "7", "8", "9"
   ]
 
-arrayVariables = [
+shellArrayVariables = [
     "BASH_ALIASES", "BASH_ARGC", "BASH_ARGV", "BASH_CMDS", "BASH_LINENO",
     "BASH_REMATCH", "BASH_SOURCE", "BASH_VERSINFO", "COMP_WORDS", "COPROC",
     "DIRSTACK", "FUNCNAME", "GROUPS", "MAPFILE", "PIPESTATUS", "COMPREPLY"
   ]
 
+portageArrayVariables = [
+    "PATCHES"
+  ]
+
 commonCommands = [
     "admin", "alias", "ar", "asa", "at", "awk", "basename", "batch",
     "bc", "bg", "break", "c99", "cal", "cat", "cd", "cflow", "chgrp",