1 files changed, 5 insertions, 0 deletions
diff --git a/evaluator.h b/evaluator.h
index d969afe..5de3ce1 100644
--- a/evaluator.h
+++ b/evaluator.h
@@ -40,6 +40,11 @@ typedef struct {
     char *string;
 } RESULT;
 
+/* strndup() may be not available on several platforms */
+#ifndef HAVE_STRNDUP
+char *strndup(const char *source, size_t len);
+#endif
+
 int SetVariable(const char *name, RESULT * value);
 int SetVariableNumeric(const char *name, const double value);
 int SetVariableString(const char *name, const char *value);