1 files changed, 4 insertions, 0 deletions
diff --git a/ruby-runner.c b/ruby-runner.c
index 99be4a0013..b5a2e50659 100644
--- a/ruby-runner.c
+++ b/ruby-runner.c
@@ -43,6 +43,10 @@ insert_env_path(const char *envname, const char *paths, size_t size, int prepend
     setenv(envname, env, 1);
 }
 
+/* force to link libm for fiddle test */
+#include <math.h>
+double (*const ruby_libm_func)(double) = log;
+
 #define EXTOUT_DIR BUILDDIR"/"EXTOUT
 int
 main(int argc, char **argv)