diff --git a/Makefile.am b/Makefile.am
index b7500bc..7aefce4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -119,12 +119,6 @@ noverify_tests_SOURCES = src/tests.c
 noverify_tests_CPPFLAGS = $(SECP_INCLUDES) $(SECP_TEST_INCLUDES) $(SECP_CONFIG_DEFINES)
 noverify_tests_LDADD = $(SECP_LIBS) $(SECP_TEST_LIBS) $(COMMON_LIB) $(PRECOMPUTED_LIB)
 noverify_tests_LDFLAGS = -static
-if VALGRIND_ENABLED
-noinst_PROGRAMS += ctime_tests
-ctime_tests_SOURCES = src/ctime_tests.c
-ctime_tests_LDADD = libsecp256k1.la $(SECP_LIBS) $(COMMON_LIB)
-ctime_tests_CPPFLAGS = $(SECP_CONFIG_DEFINES)
-endif
 if !ENABLE_COVERAGE
 TESTS += tests
 noinst_PROGRAMS += tests
@@ -135,6 +129,13 @@ tests_LDFLAGS  = $(noverify_tests_LDFLAGS)
 endif
 endif
 
+if USE_CTIME_TESTS
+noinst_PROGRAMS += ctime_tests
+ctime_tests_SOURCES = src/ctime_tests.c
+ctime_tests_LDADD = libsecp256k1.la $(SECP_LIBS) $(COMMON_LIB)
+ctime_tests_CPPFLAGS = $(SECP_CONFIG_DEFINES)
+endif
+
 if USE_EXHAUSTIVE_TESTS
 noinst_PROGRAMS += exhaustive_tests
 exhaustive_tests_SOURCES = src/tests_exhaustive.c
diff --git a/configure.ac b/configure.ac
index 88b0ee5..cb5d039 100644
--- a/configure.ac
+++ b/configure.ac
@@ -142,6 +142,10 @@ AC_ARG_ENABLE(tests,
     AS_HELP_STRING([--enable-tests],[compile tests [default=yes]]), [],
     [SECP_SET_DEFAULT([enable_tests], [yes], [yes])])
 
+AC_ARG_ENABLE(ctime_tests,
+    AS_HELP_STRING([--enable-ctime-tests],[compile constant-time tests [default=yes if valgrind enabled]]), [],
+    [SECP_SET_DEFAULT([enable_ctime_tests], [auto], [auto])])
+
 AC_ARG_ENABLE(experimental,
     AS_HELP_STRING([--enable-experimental],[allow experimental configure options [default=no]]), [],
     [SECP_SET_DEFAULT([enable_experimental], [no], [yes])])
@@ -225,7 +229,10 @@ else
     enable_valgrind=yes
   fi
 fi
-AM_CONDITIONAL([VALGRIND_ENABLED],[test "$enable_valgrind" = "yes"])
+
+if test x"$enable_ctime_tests" = x"auto"; then
+    enable_ctime_tests=$enable_valgrind
+fi
 
 if test x"$enable_coverage" = x"yes"; then
     SECP_CONFIG_DEFINES="$SECP_CONFIG_DEFINES -DCOVERAGE=1"
@@ -407,6 +414,7 @@ AC_SUBST(SECP_CFLAGS)
 AC_SUBST(SECP_CONFIG_DEFINES)
 AM_CONDITIONAL([ENABLE_COVERAGE], [test x"$enable_coverage" = x"yes"])
 AM_CONDITIONAL([USE_TESTS], [test x"$enable_tests" != x"no"])
+AM_CONDITIONAL([USE_CTIME_TESTS], [test x"$enable_ctime_tests" = x"yes"])
 AM_CONDITIONAL([USE_EXHAUSTIVE_TESTS], [test x"$enable_exhaustive_tests" != x"no"])
 AM_CONDITIONAL([USE_EXAMPLES], [test x"$enable_examples" != x"no"])
 AM_CONDITIONAL([USE_BENCHMARK], [test x"$enable_benchmark" = x"yes"])
@@ -428,6 +436,7 @@ echo "Build Options:"
 echo "  with external callbacks = $enable_external_default_callbacks"
 echo "  with benchmarks         = $enable_benchmark"
 echo "  with tests              = $enable_tests"
+echo "  with ctime tests        = $enable_ctime_tests"
 echo "  with coverage           = $enable_coverage"
 echo "  with examples           = $enable_examples"
 echo "  module ecdh             = $enable_module_ecdh"