diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 <!-- -*- Markdown -*- -->
 
+## 0.1.3.3
+
+- Use Haskell implementation test instead of flag test in .cabal
+
 ## 0.1.3.2
 
 - Apply generic instances to schema queries.
diff --git a/relational-schemas.cabal b/relational-schemas.cabal
--- a/relational-schemas.cabal
+++ b/relational-schemas.cabal
@@ -1,5 +1,5 @@
 name:                relational-schemas
-version:             0.1.3.2
+version:             0.1.3.3
 synopsis:            RDBMSs' schema templates for relational-query
 description:         This package contains some RDBMSs' schema structure definitions.
                      Supported RDBMS schemas are below:
@@ -25,10 +25,6 @@
                      , GHC == 7.4.1, GHC == 7.4.2
 extra-source-files:  ChangeLog.md
 
-flag ghc74-generic
-  description: Enable for generic programming using old ghc. If true use ghc-prim.
-  default:     False
-
 library
   exposed-modules:
                        Database.Relational.Schema.DB2Syscat.Columns
@@ -84,7 +80,8 @@
                        , bytestring
 
                        , relational-query >= 0.9
-  if flag(ghc74-generic)
+
+  if impl(ghc == 7.4.*)
     build-depends:        ghc-prim == 0.2.*
 
   hs-source-dirs:      src