diff --git a/src/compiler/GF/Command/Importing.hs b/src/compiler/GF/Command/Importing.hs
index f9c04efd7..d8e498c96 100644
--- a/src/compiler/GF/Command/Importing.hs
+++ b/src/compiler/GF/Command/Importing.hs
@@ -20,6 +20,7 @@ import System.Directory
 import qualified Data.Set as Set
 import qualified Data.Map as Map
 import Control.Monad(foldM)
+import Control.Exception(catch,throwIO)
 
 -- import a grammar in an environment where it extends an existing grammar
 importGrammar :: Maybe PGF -> Options -> [FilePath] -> IO (Maybe PGF)
@@ -65,7 +66,13 @@ importPGF opts Nothing    f
                                         putStr ("(Boot image "++f'++") ")
                                         fmap Just (bootNGF f f')
   | otherwise                      = fmap Just (readPGF f)
-importPGF opts (Just pgf) f        = fmap Just (modifyPGF pgf (mergePGF f))
+importPGF opts (Just pgf) f        = fmap Just (modifyPGF pgf (mergePGF f) `catch`
+                                                (\e@(PGFError loc msg) ->
+                                                      if msg == "The abstract syntax names doesn't match"
+                                                        then do putStrLn (msg++", previous concretes discarded.")
+                                                                readPGF f
+                                                        else throwIO e))
+
 
 importSource :: Options -> [FilePath] -> IO (ModuleName,SourceGrammar)
 importSource opts files = fmap snd (batchCompile opts files)
diff --git a/src/runtime/c/pgf/reader.cxx b/src/runtime/c/pgf/reader.cxx
index 0b7c1d50a..693a119d6 100644
--- a/src/runtime/c/pgf/reader.cxx
+++ b/src/runtime/c/pgf/reader.cxx
@@ -395,10 +395,15 @@ void PgfReader::merge_abstract(ref<PgfAbstr> abstract)
 {
     this->abstract = abstract;
 
-    read_name(); // ?
-	merge_namespace<PgfFlag>(&PgfReader::read_flag); // ?
-    merge_namespace<PgfAbsFun>(&PgfReader::read_absfun); // ?
-    merge_namespace<PgfAbsCat>(&PgfReader::read_abscat); // ?
+    ref<PgfText> name = read_name();
+    int cmp = textcmp(&(*abstract->name), &(*name));
+    PgfDB::free(name);
+    if (cmp != 0)
+        throw pgf_error("The abstract syntax names doesn't match");
+
+	merge_namespace<PgfFlag>(&PgfReader::read_flag);
+    merge_namespace<PgfAbsFun>(&PgfReader::read_absfun);
+    merge_namespace<PgfAbsCat>(&PgfReader::read_abscat);
 }
 
 ref<PgfLParam> PgfReader::read_lparam()