diff --git a/library/timing.c b/library/timing.c
index f2f0a43..b1f72fe 100644
--- a/library/timing.c
+++ b/library/timing.c
@@ -401,6 +401,7 @@
     uint32_t a = 0, b = 0;
     mbedtls_timing_delay_context ctx;
 
+    memset(&ctx, 0, sizeof(ctx));
     if (verbose != 0) {
         mbedtls_printf("  TIMING tests note: will take some time!\n");
     }