diff --git a/compiler/main/GhcMake.hs b/compiler/main/GhcMake.hs
index 41d4f1c59251555aee941539361545eca0f37d2e..843def11920d948d81a8139259c637a99bda01e8 100644
--- a/compiler/main/GhcMake.hs
+++ b/compiler/main/GhcMake.hs
@@ -1886,13 +1886,11 @@ summariseModule hsc_env old_summary_map is_boot (L loc wanted_mod)
                 | isJust (ml_hs_file location) ->
                         -- Home package
                          just_found location mod
-                | otherwise ->
-                        -- Drop external-pkg
-                        ASSERT(moduleUnitId mod /= thisPackage dflags)
-                        return Nothing
 
-             err -> return $ Just $ Left $ noModError dflags loc wanted_mod err
+             _ -> return Nothing
                         -- Not found
+                        -- (If it is TRULY not found at all, we'll
+                        -- error when we actually try to compile)
 
     just_found location mod = do
                 -- Adjust location to point to the hs-boot source file,
diff --git a/testsuite/tests/cabal/cabal07/cabal07.stderr b/testsuite/tests/cabal/cabal07/cabal07.stderr
index 097f23fdc8c297271aa2c90bba5950cc7e3321dc..b3cfe5b15281bfe6641bafb54d96f5525ec44361 100644
--- a/testsuite/tests/cabal/cabal07/cabal07.stderr
+++ b/testsuite/tests/cabal/cabal07/cabal07.stderr
@@ -1,6 +1,6 @@
 
-Q.hs:3:8: error:
-    Could not find module ‘Data.Set’
-    It is a member of the hidden package ‘containers-0.5.6.3@containers-0.5.6.3’.
+Q.hs:3:1: error:
+    Failed to load interface for ‘Data.Set’
+    It is a member of the hidden package ‘containers-0.5.7.0’.
     Perhaps you need to add ‘containers’ to the build-depends in your .cabal file.
     Use -v to see a list of the files searched for.
diff --git a/testsuite/tests/driver/driver063.stderr b/testsuite/tests/driver/driver063.stderr
index 25488b80e9be18d8b89fa0f9dd8db8f660f88f05..84ff5b6dbb712a1e456bcba188c57b2e88698192 100644
--- a/testsuite/tests/driver/driver063.stderr
+++ b/testsuite/tests/driver/driver063.stderr
@@ -1,4 +1,4 @@
 
-D063.hs:2:8:
-    Could not find module ‘A063’
+D063.hs:2:1: error:
+    Failed to load interface for ‘A063’
     It is not a module in the current program, or in any known package.
diff --git a/testsuite/tests/ghc-e/should_run/T2636.stderr b/testsuite/tests/ghc-e/should_run/T2636.stderr
index 98c109e92d88a1b9b8debbb021f477f2f1f563d5..1a7912735c608ee9842ca9399181b25113563fdf 100644
--- a/testsuite/tests/ghc-e/should_run/T2636.stderr
+++ b/testsuite/tests/ghc-e/should_run/T2636.stderr
@@ -1,4 +1,4 @@
 
-T2636.hs:1:8:
-    Could not find module ‘MissingModule’
+T2636.hs:1:1: error:
+    Failed to load interface for ‘MissingModule’
     Use -v to see a list of the files searched for.