diff --git a/lib/common/fuzzers/utils_fuzzer.c b/lib/common/fuzzers/utils_fuzzer.c
index 2cb3a5339b..93b58224c0 100644
--- a/lib/common/fuzzers/utils_fuzzer.c
+++ b/lib/common/fuzzers/utils_fuzzer.c
@@ -1,34 +1,35 @@
 /*
  * Copyright 2024 the Pacemaker project contributors
  *
  * The version control history for this file may have further details.
  *
  * This source code is licensed under the GNU Lesser General Public License
  * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
  */
 
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>
 
 #include <crm/common/util.h>
 #include <crm/common/internal.h>
 
 int
 LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
 {
     char *ns = NULL;
     guint result = 0U;
 
-    if (size < 10) {
-        return -1; // Do not add input to testing corpus
+    if (size > 0) {
+        ns = pcmk__assert_alloc(1, size + 1);
+        memcpy(ns, data, size);
+        ns[size] = '\0';
     }
-    ns = pcmk__assert_alloc(1, size + 1);
-    memcpy(ns, data, size);
-    ns[size] = '\0';
 
+    pcmk_str_is_infinity(ns);
+    pcmk_str_is_minus_infinity(ns);
     pcmk_parse_interval_spec(ns, &result);
 
     free(ns);
     return 0;
 }