diff --git a/libs/spandsp/src/at_interpreter.c b/libs/spandsp/src/at_interpreter.c
index 5d488a2685..30265cb8fb 100644
--- a/libs/spandsp/src/at_interpreter.c
+++ b/libs/spandsp/src/at_interpreter.c
@@ -40,6 +40,9 @@
 #include <fcntl.h>
 #include <memory.h>
 #include <string.h>
+#if defined(HAVE_STRINGS_H)
+#include <strings.h>
+#endif
 #include <ctype.h>
 #include <assert.h>