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
@@ -5176,6 +5176,15 @@
 int main(int argc, char **argv) {
     unsigned char seed16[16] = {0};
     unsigned char run32[32] = {0};
+
+    /* Disable buffering for stdout to improve reliability of getting
+     * diagnostic information. Happens right at the start of main because
+     * setbuf must be used before any other operation on the stream. */
+    setbuf(stdout, NULL);
+    /* Also disable buffering for stderr because it's not guaranteed that it's
+     * unbuffered on all systems. */
+    setbuf(stderr, NULL);
+
     /* find iteration count */
     if (argc > 1) {
         count = strtol(argv[1], NULL, 0);
diff --git a/src/secp256k1/travis/build_autotools.sh b/src/secp256k1/travis/build_autotools.sh
--- a/src/secp256k1/travis/build_autotools.sh
+++ b/src/secp256k1/travis/build_autotools.sh
@@ -35,6 +35,12 @@
   $AUTOTOOLS_EXTRA_FLAGS \
   $USE_HOST
 
+print_logs() {
+  cat tests.log || :
+  cat exhaustive_tests.log || :
+}
+trap 'print_logs' ERR
+
 make -j2 $AUTOTOOLS_TARGET
 
 popd