diff --git a/gap-semigroups.spec b/gap-semigroups.spec
index 85c0d91..8563b34 100644
--- a/gap-semigroups.spec
+++ b/gap-semigroups.spec
@@ -26,6 +26,7 @@ URL:            https://semigroups.github.io/Semigroups/
 #Git-Clone:     https://github.com/semigroups/Semigroups
 Source:         https://github.com/semigroups/Semigroups/releases/download/v%version/semigroups-%version.tar.gz
 BuildRequires:  c++_compiler
+BuildRequires:  fdupes
 BuildRequires:  gap-devel >= 4.12
 BuildRequires:  gap-rpm-devel
 BuildRequires:  gmp-devel
@@ -67,9 +68,11 @@ autoreconf -fi
 rm -Rf libsemigroups
 %gappkg_simple_install
 pushd "%buildroot/$fmoddir/"
-rm -Rfv Makefile* configure* src/
+rm -Rfv Makefile* configure* cnf/ src/ gapbind14/src/ gapbind14/include/
 popd
-find "%buildroot" -name "*.orig" -print -delete
+find "%buildroot" "(" -name "*.orig" -o -name .gitignore -o \
+	-name .dirstamp -o -name .clang-format -o -name .ccls ")" -print -delete
+%fdupes %buildroot/%_prefix
 
 %files -f %name.files