diff --git a/library/lmots.h b/library/lmots.h
index f6daa0bcca..d0379e3a2d 100644
--- a/library/lmots.h
+++ b/library/lmots.h
@@ -139,6 +139,10 @@ typedef struct {
 } mbedtls_lmots_private_t;
 #endif /* MBEDTLS_LMS_PRIVATE */
 
+#if defined(MBEDTLS_TEST_HOOKS)
+extern int( *mbedtls_lmots_sign_private_key_invalidated_hook )( unsigned char * );
+#endif /* defined(MBEDTLS_TEST_HOOKS) */
+
 /**
  * \brief                    This function converts an unsigned int into a
  *                           network-byte-order (big endian) string.
diff --git a/tests/suites/test_suite_lmots.function b/tests/suites/test_suite_lmots.function
index d7067dfe00..dd8a665d58 100644
--- a/tests/suites/test_suite_lmots.function
+++ b/tests/suites/test_suite_lmots.function
@@ -3,8 +3,6 @@
 #include "mbedtls/lms.h"
 
 #if defined(MBEDTLS_TEST_HOOKS)
-extern int( *mbedtls_lmots_sign_private_key_invalidated_hook )( unsigned char * );
-
 int check_lmots_private_key_for_leak(unsigned char * sig)
 {
     size_t idx;