diff --git a/src/secp256k1/src/tests.c b/src/secp256k1/src/tests.c
--- a/src/secp256k1/src/tests.c
+++ b/src/secp256k1/src/tests.c
@@ -4372,8 +4372,10 @@
     secp256k1_scalar one;
     secp256k1_scalar msg, key;
     secp256k1_scalar sigr, sigs;
-    int recid;
     int getrec;
+    /* Initialize recid to suppress a false positive -Wconditional-uninitialized in clang.
+       VG_UNDEF ensures that valgrind will still treat the variable as uninitialized. */
+    int recid = -1; VG_UNDEF(&recid, sizeof(recid));
     random_scalar_order_test(&msg);
     random_scalar_order_test(&key);
     secp256k1_ecmult_gen(&ctx->ecmult_gen_ctx, &pubj, &key);