diff --git a/configure.ac b/configure.ac
index 49be89c..2b958f8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -53,6 +53,14 @@ if test x$cxxmph = xtrue; then
 fi
 AM_CONDITIONAL([USE_CXXMPH], [test "$cxxmph" = true])
 
+AC_ENABLE_BENCHMARKS
+if test x$benchmarks = xtrue; then
+  AC_LANG_PUSH([C++])
+  AC_CHECK_HEADERS([hopscotch_map.h])
+  AC_LANG_POP([C++])
+fi
+AM_CONDITIONAL([USE_BENCHMARKS], [test "$benchmarks" = true])
+
 # Unit tests based on the check library. Disabled by default.
 # We do not use pkg-config because it is inconvenient for all developers to
 # have check library installed.
diff --git a/cxxmph/Makefile.am b/cxxmph/Makefile.am
index b542000..4ebaccb 100644
--- a/cxxmph/Makefile.am
+++ b/cxxmph/Makefile.am
@@ -5,7 +5,9 @@ if USE_LIBCHECK
   check_LTLIBRARIES = libcxxmph_test.la
 endif
 
-noinst_PROGRAMS = bm_map # bm_index - disabled because of cmph dependency
+if USE_BENCHMARKS
+  noinst_PROGRAMS = bm_map # bm_index - disabled because of cmph dependency
+endif
 bin_PROGRAMS = cxxmph
 
 cxxmph_includedir = $(includedir)/cxxmph/
diff --git a/cxxmph/bm_map.cc b/cxxmph/bm_map.cc
index a907e47..09a3bc5 100644
--- a/cxxmph/bm_map.cc
+++ b/cxxmph/bm_map.cc
@@ -1,7 +1,7 @@
 #include <string>
 #include <unordered_map>
+
 #include "hopscotch_map.h"
-#include "flat_hash_map.hpp"
 
 #include "bm_common.h"
 #include "mph_map.h"
@@ -104,27 +104,23 @@ int main(int argc, char** argv) {
   Benchmark::Register(new BM_CreateUrls<mph_map<StringPiece, StringPiece>>("URLS100k"));
   Benchmark::Register(new BM_CreateUrls<sparse_hash_map<StringPiece, StringPiece>>("URLS100k"));
   Benchmark::Register(new BM_CreateUrls<tsl::hopscotch_map<StringPiece, StringPiece>>("URLS100k"));
-  Benchmark::Register(new BM_CreateUrls<ska::flat_hash_map<StringPiece, StringPiece>>("URLS100k"));
 
   Benchmark::Register(new BM_SearchUrls<dense_hash_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0));
   Benchmark::Register(new BM_SearchUrls<std::unordered_map<StringPiece, StringPiece, Murmur3StringPiece>>("URLS100k", 10*1000 * 1000, 0));
   Benchmark::Register(new BM_SearchUrls<mph_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0));
   Benchmark::Register(new BM_SearchUrls<sparse_hash_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0));
   Benchmark::Register(new BM_SearchUrls<tsl::hopscotch_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0));
-  Benchmark::Register(new BM_SearchUrls<ska::flat_hash_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0));
 
   Benchmark::Register(new BM_SearchUrls<dense_hash_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0.9));
   Benchmark::Register(new BM_SearchUrls<std::unordered_map<StringPiece, StringPiece, Murmur3StringPiece>>("URLS100k", 10*1000 * 1000, 0.9));
   Benchmark::Register(new BM_SearchUrls<mph_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0.9));
   Benchmark::Register(new BM_SearchUrls<sparse_hash_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0.9));
   Benchmark::Register(new BM_SearchUrls<tsl::hopscotch_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0.9));
-  Benchmark::Register(new BM_SearchUrls<ska::flat_hash_map<StringPiece, StringPiece>>("URLS100k", 10*1000 * 1000, 0.9));
 
   Benchmark::Register(new BM_SearchUint64<dense_hash_map<uint64_t, uint64_t>>);
   Benchmark::Register(new BM_SearchUint64<std::unordered_map<uint64_t, uint64_t>>);
   Benchmark::Register(new BM_SearchUint64<mph_map<uint64_t, uint64_t>>);
   Benchmark::Register(new BM_SearchUint64<sparse_hash_map<uint64_t, uint64_t>>);
   Benchmark::Register(new BM_SearchUint64<tsl::hopscotch_map<uint64_t, uint64_t>>);
-  Benchmark::Register(new BM_SearchUint64<ska::flat_hash_map<uint64_t, uint64_t>>);
   Benchmark::RunAll();
 }
diff --git a/m4/acinclude.m4 b/m4/acinclude.m4
index 07e81d1..370d63b 100644
--- a/m4/acinclude.m4
+++ b/m4/acinclude.m4
@@ -5,3 +5,11 @@ AC_DEFUN([AC_ENABLE_CXXMPH], [AC_ARG_ENABLE([cxxmph],
 		no)  cxxmph=false ;;
 		*) AC_MSG_ERROR([bad value ${enableval} for --enable-cxxmph]) ;;
 	esac],[cxxmph=false])])
+
+AC_DEFUN([AC_ENABLE_BENCHMARKS], [AC_ARG_ENABLE([benchmarks],
+	[  --enable-benchmarks	enable cxxmph benchmarks against other libs ],
+	[case "${enableval}" in
+		yes) benchmarks=true ;;
+		no)  benchmarks=false ;;
+		*) AC_MSG_ERROR([bad value ${enableval} for --enable-benchmarks]) ;;
+	esac],[benchmarks=false])])