diff --git a/lib/util/fatal.c b/lib/util/fatal.c
index cf2303ffc..7d2e09d18 100644
--- a/lib/util/fatal.c
+++ b/lib/util/fatal.c
@@ -239,8 +239,10 @@ warning(const char *errstr, const char *fmt, va_list ap)
             fputs(": ", stderr);
             fputs(errstr, stderr);
         }
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
         if (sudo_term_is_raw(fileno(stderr)))
             putc('\r', stderr);
+#endif
         putc('\n', stderr);
     }
 
diff --git a/lib/util/getentropy.c b/lib/util/getentropy.c
index dc5c91c02..03526fad2 100644
--- a/lib/util/getentropy.c
+++ b/lib/util/getentropy.c
@@ -80,6 +80,13 @@
 #include "sudo_digest.h"
 #include "sudo_rand.h"
 
+/* Only use getrandom(2) when fuzzing. */
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+# if !defined(SYS_getrandom) || !defined(GRND_NONBLOCK)
+#  undef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+# endif
+#endif
+
 #if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
 # define MAP_ANON MAP_ANONYMOUS
 #endif
@@ -106,6 +113,7 @@
 int	sudo_getentropy(void *buf, size_t len);
 
 static int getentropy_getrandom(void *buf, size_t len);
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
 static int getentropy_sysctl(void *buf, size_t len);
 static int getentropy_urandom(void *buf, size_t len, const char *path,
     int devfscheck);
@@ -114,22 +122,7 @@ static int gotdata(char *buf, size_t len);
 #ifdef HAVE_DL_ITERATE_PHDR
 static int getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data);
 #endif
-
-static void *
-mmap_anon(void *addr, size_t len, int prot, int flags, off_t offset)
-{
-#ifdef MAP_ANON
-	return mmap(addr, len, prot, flags | MAP_ANON, -1, offset);
-#else
-	int fd;
-
-	if ((fd = open("/dev/zero", O_RDWR)) == -1)
-		return MAP_FAILED;
-	addr = mmap(addr, len, prot, flags, fd, offset);
-	close(fd);
-	return addr;
-#endif
-}
+#endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */
 
 int
 sudo_getentropy(void *buf, size_t len)
@@ -145,7 +138,9 @@ sudo_getentropy(void *buf, size_t len)
 	if (ret != -1)
 		return (ret);
 
-#ifdef HAVE_OPENSSL
+#if !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
+
+#if defined(HAVE_OPENSSL)
 	if (RAND_bytes(buf, len) == 1)
 		return (0);
 #endif
@@ -193,14 +188,44 @@ sudo_getentropy(void *buf, size_t len)
 		return (ret);
 
 	errno = EIO;
+#endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */
 	return (ret);
 }
 
-/*
- * This is an open source non-commercial project. Dear PVS-Studio, please check it.
- * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
- */
+#if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
+static int
+getentropy_getrandom(void *buf, size_t len)
+{
+	int pre_errno = errno;
+	int ret;
 
+        /*
+         * Try descriptor-less getrandom(), in non-blocking mode.
+         *
+         * The design of Linux getrandom is broken.  It has an
+         * uninitialized phase coupled with blocking behaviour, which
+         * is unacceptable from within a library at boot time without
+         * possible recovery. See http://bugs.python.org/issue26839#msg267745
+         */
+	do {
+		ret = syscall(SYS_getrandom, buf, len, GRND_NONBLOCK);
+	} while (ret == -1 && errno == EINTR);
+
+	if (ret < 0 || (size_t)ret != len)
+		return (-1);
+	errno = pre_errno;
+	return (0);
+}
+#else
+static int
+getentropy_getrandom(void *buf, size_t len)
+{
+	errno = ENOTSUP;
+	return (-1);
+}
+#endif
+
+#if !defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
 /*
  * Basic validity checking; wish we could do better.
  */
@@ -338,39 +363,6 @@ getentropy_sysctl(void *buf, size_t len)
 }
 #endif
 
-#if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
-static int
-getentropy_getrandom(void *buf, size_t len)
-{
-	int pre_errno = errno;
-	int ret;
-
-        /*
-         * Try descriptor-less getrandom(), in non-blocking mode.
-         *
-         * The design of Linux getrandom is broken.  It has an
-         * uninitialized phase coupled with blocking behaviour, which
-         * is unacceptable from within a library at boot time without
-         * possible recovery. See http://bugs.python.org/issue26839#msg267745
-         */
-	do {
-		ret = syscall(SYS_getrandom, buf, len, GRND_NONBLOCK);
-	} while (ret == -1 && errno == EINTR);
-
-	if (ret < 0 || (size_t)ret != len)
-		return (-1);
-	errno = pre_errno;
-	return (0);
-}
-#else
-static int
-getentropy_getrandom(void *buf, size_t len)
-{
-	errno = ENOTSUP;
-	return (-1);
-}
-#endif
-
 #ifdef HAVE_CLOCK_GETTIME
 static const int cl[] = {
 	CLOCK_REALTIME,
@@ -409,6 +401,22 @@ getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data)
 }
 #endif
 
+static void *
+mmap_anon(void *addr, size_t len, int prot, int flags, off_t offset)
+{
+#ifdef MAP_ANON
+	return mmap(addr, len, prot, flags | MAP_ANON, -1, offset);
+#else
+	int fd;
+
+	if ((fd = open("/dev/zero", O_RDWR)) == -1)
+		return MAP_FAILED;
+	addr = mmap(addr, len, prot, flags, fd, offset);
+	close(fd);
+	return addr;
+#endif
+}
+
 static int
 getentropy_fallback(void *buf, size_t len)
 {
@@ -638,5 +646,6 @@ done:
 		freezero(results, digest_len);
 	return (ret);
 }
+#endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */
 
 #endif /* HAVE_GETENTROPY */
diff --git a/lib/util/sudo_conf.c b/lib/util/sudo_conf.c
index f2cdee6f6..eab9f4518 100644
--- a/lib/util/sudo_conf.c
+++ b/lib/util/sudo_conf.c
@@ -631,7 +631,6 @@ sudo_conf_init(int conf_types)
 int
 sudo_conf_read_v1(const char *conf_file, int conf_types)
 {
-    struct stat sb;
     FILE *fp = NULL;
     int fd, ret = false;
     char *prev_locale, *line = NULL;
@@ -652,14 +651,11 @@ sudo_conf_read_v1(const char *conf_file, int conf_types)
     if (prev_locale[0] != 'C' || prev_locale[1] != '\0')
         setlocale(LC_ALL, "C");
 
-    if (conf_file != NULL) {
-	fd = open(conf_file, O_RDONLY);
-	if (fd == -1) {
-	    sudo_warn(U_("unable to open %s"), conf_file);
-	    goto done;
-	}
-    } else {
+#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+    if (conf_file == NULL) {
+	struct stat sb;
 	int error;
+
 	conf_file = _PATH_SUDO_CONF;
 	fd = sudo_secure_open_file(conf_file, ROOT_UID, -1, &sb, &error);
 	if (fd == -1) {
@@ -689,6 +685,17 @@ sudo_conf_read_v1(const char *conf_file, int conf_types)
 	    }
 	    goto done;
 	}
+    } else
+#else
+    if (conf_file == NULL)
+	conf_file = _PATH_SUDO_CONF;
+#endif /* FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION */
+    {
+	fd = open(conf_file, O_RDONLY);
+	if (fd == -1) {
+	    sudo_warn(U_("unable to open %s"), conf_file);
+	    goto done;
+	}
     }
 
     if ((fp = fdopen(fd, "r")) == NULL) {