diff --git a/fuzz/main.c b/fuzz/main.c
index 6e7c1d3..cc8e891 100644
--- a/fuzz/main.c
+++ b/fuzz/main.c
@@ -40,6 +40,7 @@
 #include <fcntl.h>
 #include <errno.h>
 #include <sys/stat.h>
+#include <dirent.h>
 
 #if defined (_MSC_VER) && ! defined (ssize_t)
 #include <basetsd.h>
@@ -50,11 +51,6 @@ typedef SSIZE_T ssize_t;
 
 #if defined (TEST_RUN) && defined (HAVE_FMEMOPEN)
 
-#include <dirent.h>
-#ifdef HAVE_ALLOCA_H
-#  include <alloca.h>
-#endif
-
 static void test_all_from(const char *dirname)
 {
 	DIR *dirp;
@@ -62,8 +58,7 @@ static void test_all_from(const char *dirname)
 
 	if ((dirp = opendir(dirname))) {
 		while ((dp = readdir(dirp))) {
-			size_t fnamesize;
-			char *fname;
+			char fname[1024];
 			int fd;
 			struct stat st;
 			uint8_t *data;
@@ -71,9 +66,7 @@ static void test_all_from(const char *dirname)
 
 			if (*dp->d_name == '.') continue;
 
-			fnamesize = strlen(dirname) + strlen(dp->d_name) + 2;
-			fname = alloca(fnamesize);
-			snprintf(fname, fnamesize, "%s/%s", dirname, dp->d_name);
+			snprintf(fname, sizeof(fname), "%s/%s", dirname, dp->d_name);
 
 			if ((fd = open(fname, O_RDONLY)) == -1) {
 				fprintf(stderr, "Failed to open %s (%d)\n", fname, errno);
@@ -88,7 +81,7 @@ static void test_all_from(const char *dirname)
 
 			data = malloc(st.st_size);
 			if ((n = read(fd, data, st.st_size)) == st.st_size) {
-				printf("testing %u bytes from '%s'\n", (int) st.st_size, fname);
+				printf("testing %d bytes from '%s'\n", (int) n, fname);
 				LLVMFuzzerTestOneInput(data, st.st_size);
 			} else
 				fprintf(stderr, "Failed to read %d bytes from %s (%d), got %d\n", (int) st.st_size, fname, errno, (int) n);
@@ -102,31 +95,27 @@ static void test_all_from(const char *dirname)
 
 int main(int argc, char **argv)
 {
-	const char *target;
-	size_t corporadirsize = sizeof(SRCDIR) + 1 + strlen(argv[0]) + 8;
-	char *corporadir = alloca(corporadirsize);
-
 	/* if VALGRIND testing is enabled, we have to call ourselves with valgrind checking */
 	if (argc == 1) {
 		const char *valgrind = getenv("TESTS_VALGRIND");
 
 		if (valgrind && *valgrind) {
-			size_t cmdsize = strlen(valgrind) + strlen(argv[0]) + 32;
-			char *cmd = alloca(cmdsize);
+			char cmd[1024];
 
-			snprintf(cmd, cmdsize, "TESTS_VALGRIND="" %s %s", valgrind, argv[0]);
+			snprintf(cmd, sizeof(cmd), "TESTS_VALGRIND="" %s %s", valgrind, argv[0]);
 			return system(cmd) != 0;
 		}
 	}
 
-	target = strrchr(argv[0], '/');
+	const char *target = strrchr(argv[0], '/');
 	target = target ? target + 1 : argv[0];
 
-	snprintf(corporadir, corporadirsize, SRCDIR "/%s.in", target);
+	char corporadir[1024];
+	snprintf(corporadir, sizeof(corporadir), SRCDIR "/%s.in", target);
 
 	test_all_from(corporadir);
 
-	snprintf(corporadir, corporadirsize, SRCDIR "/%s.repro", target);
+	snprintf(corporadir, sizeof(corporadir), SRCDIR "/%s.repro", target);
 
 	test_all_from(corporadir);