3 files changed, 19 insertions, 8 deletions
diff --git a/libraries/ghci/GHCi/BreakArray.hs b/libraries/ghci/GHCi/BreakArray.hs
index 8d0e7495ba..41a2ab498f 100644
--- a/libraries/ghci/GHCi/BreakArray.hs
+++ b/libraries/ghci/GHCi/BreakArray.hs
@@ -19,7 +19,7 @@
 module GHCi.BreakArray
     (
       BreakArray
-#ifdef GHCI
+#if defined(HAVE_INTERPRETER)
           (BA) -- constructor is exported only for ByteCodeGen
     , newBreakArray
     , getBreak
@@ -29,7 +29,7 @@ module GHCi.BreakArray
 #endif
     ) where
 
-#ifdef GHCI
+#if defined(HAVE_INTERPRETER)
 import Prelude -- See note [Why do we import Prelude here?]
 import Control.Monad
 import Data.Word
diff --git a/libraries/ghci/GHCi/InfoTable.hsc b/libraries/ghci/GHCi/InfoTable.hsc
index 87d8f8f167..826e3bc2fd 100644
--- a/libraries/ghci/GHCi/InfoTable.hsc
+++ b/libraries/ghci/GHCi/InfoTable.hsc
@@ -10,13 +10,13 @@
 --
 module GHCi.InfoTable
   (
-#ifdef GHCI
+#if defined(HAVE_INTERPRETER)
     mkConInfoTable
 #endif
   ) where
 
 import Prelude -- See note [Why do we import Prelude here?]
-#ifdef GHCI
+#if defined(HAVE_INTERPRETER)
 import Foreign
 import Foreign.C
 import GHC.Ptr
@@ -27,13 +27,13 @@ import qualified Data.ByteString as BS
 #endif
 
 ghciTablesNextToCode :: Bool
-#ifdef TABLES_NEXT_TO_CODE
+#if defined(TABLES_NEXT_TO_CODE)
 ghciTablesNextToCode = True
 #else
 ghciTablesNextToCode = False
 #endif
 
-#ifdef GHCI /* To end */
+#if defined(HAVE_INTERPRETER) /* To end */
 -- NOTE: Must return a pointer acceptable for use in the header of a closure.
 -- If tables_next_to_code is enabled, then it must point the the 'code' field.
 -- Otherwise, it should point to the start of the StgInfoTable.
@@ -387,4 +387,4 @@ wORD_SIZE = (#const SIZEOF_HSINT)
 
 conInfoTableSizeB :: Int
 conInfoTableSizeB = wORD_SIZE + itblSize
-#endif /* GHCI */
+#endif /* HAVE_INTERPRETER */
diff --git a/libraries/ghci/ghci.cabal.in b/libraries/ghci/ghci.cabal.in
index 728927d3ce..f4c49137cc 100644
--- a/libraries/ghci/ghci.cabal.in
+++ b/libraries/ghci/ghci.cabal.in
@@ -22,6 +22,11 @@ Flag ghci
     Default: False
     Manual: True
 
+Flag ext-interp
+    Description: Build external interpreter support
+    Default: True
+    Manual: True
+
 source-repository head
     type:     git
     location: https://gitlab.haskell.org/ghc/ghc.git
@@ -48,7 +53,7 @@ library
         UnboxedTuples
 
     if flag(ghci)
-        CPP-Options: -DGHCI
+        CPP-Options: -DHAVE_INTERNAL_INTERPRETER
         exposed-modules:
             GHCi.Run
             GHCi.CreateBCO
@@ -56,6 +61,12 @@ library
             GHCi.Signals
             GHCi.TH
 
+    if flag(ext-interp)
+        CPP-Options: -DHAVE_EXTERNAL_INTERPRETER
+
+    if flag(ghci) || flag(ext-interp)
+        CPP-Options: -DHAVE_INTERPRETER
+
     include-dirs: @FFIIncludeDir@
 
     exposed-modules: