diff --git a/icu.spec b/icu.spec
index efb20f6..32af44f 100644
--- a/icu.spec
+++ b/icu.spec
@@ -179,7 +179,8 @@ pushd data/
 cp in/icudt%{amajor}l.dat out/
 %else
 LD_LIBRARY_PATH="../lib:../stubdata:../tools/ctestfw:$LD_LIBRARY_PATH" \
-	../bin/icupkg -tb ./in/icudt%{amajor}l.dat ./out/icudt%{amajor}b.dat
+	../bin/icupkg -tb in/icudt%{amajor}l.dat out/icudt%{amajor}b.dat
+! cmp in/icudt%{amajor}l.dat out/icudt%{amajor}b.dat
 %endif
 popd