diff --git a/plugins/sudoers/digestname.c b/plugins/sudoers/digestname.c
index e501de474..f70b48fb1 100644
--- a/plugins/sudoers/digestname.c
+++ b/plugins/sudoers/digestname.c
@@ -29,7 +29,7 @@
 #include "parse.h"
 
 const char *
-digest_type_to_name(int digest_type)
+digest_type_to_name(unsigned int digest_type)
 {
     const char *digest_name;
     debug_decl(digest_type_to_name, SUDOERS_DEBUG_UTIL);
diff --git a/plugins/sudoers/filedigest.c b/plugins/sudoers/filedigest.c
index 24807aa6c..e59cc7a6a 100644
--- a/plugins/sudoers/filedigest.c
+++ b/plugins/sudoers/filedigest.c
@@ -34,7 +34,8 @@
 #include "sudo_digest.h"
 
 unsigned char *
-sudo_filedigest(int fd, const char *file, int digest_type, size_t *digest_len)
+sudo_filedigest(int fd, const char *file, unsigned int digest_type,
+    size_t *digest_len)
 {
     unsigned char *file_digest = NULL;
     unsigned char buf[32 * 1024];
@@ -46,7 +47,7 @@ sudo_filedigest(int fd, const char *file, int digest_type, size_t *digest_len)
 
     *digest_len = sudo_digest_getlen(digest_type);
     if (*digest_len == (size_t)-1) {
-	sudo_warnx(U_("unsupported digest type %d for %s"), digest_type, file);
+	sudo_warnx(U_("unsupported digest type %u for %s"), digest_type, file);
 	goto bad;
     }
 
diff --git a/plugins/sudoers/gram.c b/plugins/sudoers/gram.c
index b45bcdfe3..977bc5e5e 100644
--- a/plugins/sudoers/gram.c
+++ b/plugins/sudoers/gram.c
@@ -164,7 +164,7 @@ static bool add_userspec(struct member *, struct privilege *);
 static struct defaults *new_default(char *, char *, short);
 static struct member *new_member(char *, int);
 static struct sudo_command *new_command(char *, char *);
-static struct command_digest *new_digest(int, char *);
+static struct command_digest *new_digest(unsigned int, char *);
 static void alias_error(const char *name, int errnum);
 
 #line 165 "gram.c"
@@ -3548,7 +3548,7 @@ new_command(char *cmnd, char *args)
 }
 
 static struct command_digest *
-new_digest(int digest_type, char *digest_str)
+new_digest(unsigned int digest_type, char *digest_str)
 {
     struct command_digest *digest;
     debug_decl(new_digest, SUDOERS_DEBUG_PARSER);
diff --git a/plugins/sudoers/gram.y b/plugins/sudoers/gram.y
index b579f22c7..4c4b29791 100644
--- a/plugins/sudoers/gram.y
+++ b/plugins/sudoers/gram.y
@@ -81,7 +81,7 @@ static bool add_userspec(struct member *, struct privilege *);
 static struct defaults *new_default(char *, char *, short);
 static struct member *new_member(char *, int);
 static struct sudo_command *new_command(char *, char *);
-static struct command_digest *new_digest(int, char *);
+static struct command_digest *new_digest(unsigned int, char *);
 static void alias_error(const char *name, int errnum);
 %}
 
@@ -1365,7 +1365,7 @@ new_command(char *cmnd, char *args)
 }
 
 static struct command_digest *
-new_digest(int digest_type, char *digest_str)
+new_digest(unsigned int digest_type, char *digest_str)
 {
     struct command_digest *digest;
     debug_decl(new_digest, SUDOERS_DEBUG_PARSER);
diff --git a/plugins/sudoers/parse.h b/plugins/sudoers/parse.h
index b958331af..c012696a7 100644
--- a/plugins/sudoers/parse.h
+++ b/plugins/sudoers/parse.h
@@ -466,10 +466,10 @@ int parse_timeout(const char *timestr);
 time_t parse_gentime(const char *expstr);
 
 /* filedigest.c */
-unsigned char *sudo_filedigest(int fd, const char *file, int digest_type, size_t *digest_len);
+unsigned char *sudo_filedigest(int fd, const char *file, unsigned int digest_type, size_t *digest_len);
 
 /* digestname.c */
-const char *digest_type_to_name(int digest_type);
+const char *digest_type_to_name(unsigned int digest_type);
 
 /* parse.c */
 struct sudo_nss_list;
diff --git a/plugins/sudoers/regress/parser/check_digest.c b/plugins/sudoers/regress/parser/check_digest.c
index c784b2b04..4449bb0a5 100644
--- a/plugins/sudoers/regress/parser/check_digest.c
+++ b/plugins/sudoers/regress/parser/check_digest.c
@@ -46,7 +46,8 @@ static const char *test_strings[NUM_TESTS] = {
 };
 
 static unsigned char *
-check_digest(int digest_type, const char *buf, size_t buflen, size_t *digest_len)
+check_digest(unsigned int digest_type, const char *buf, size_t buflen,
+    size_t *digest_len)
 {
     char tfile[] = "digest.XXXXXX";
     unsigned char *digest = NULL;
@@ -86,7 +87,7 @@ main(int argc, char *argv[])
     unsigned char *digest;
     unsigned int i, j;
     size_t digest_len;
-    int digest_type;
+    unsigned int digest_type;
 
     initprogname(argc > 0 ? argv[0] : "check_digest");
 
diff --git a/plugins/sudoers/toke.c b/plugins/sudoers/toke.c
index e91b13a45..700589ad3 100644
--- a/plugins/sudoers/toke.c
+++ b/plugins/sudoers/toke.c
@@ -3095,7 +3095,7 @@ struct sudolinebuf sudolinebuf;	/* sudoers line being parsed. */
 
 static bool continued, sawspace;
 static int prev_state;
-static int digest_type = -1;
+static unsigned int digest_type = SUDO_DIGEST_INVALID;
 
 static bool pop_include(void);
 static yy_size_t sudoers_input(char *buf, yy_size_t max_size);
@@ -5654,7 +5654,7 @@ init_lexer(void)
     keepopen = false;
     sawspace = false;
     continued = false;
-    digest_type = -1;
+    digest_type = SUDO_DIGEST_INVALID;
     prev_state = INITIAL;
     BEGIN INITIAL;
 
diff --git a/plugins/sudoers/toke.l b/plugins/sudoers/toke.l
index c732645eb..548b111b3 100644
--- a/plugins/sudoers/toke.l
+++ b/plugins/sudoers/toke.l
@@ -61,7 +61,7 @@ struct sudolinebuf sudolinebuf;	/* sudoers line being parsed. */
 
 static bool continued, sawspace;
 static int prev_state;
-static int digest_type = -1;
+static unsigned int digest_type = SUDO_DIGEST_INVALID;
 
 static bool pop_include(void);
 static yy_size_t sudoers_input(char *buf, yy_size_t max_size);
@@ -1107,7 +1107,7 @@ init_lexer(void)
     keepopen = false;
     sawspace = false;
     continued = false;
-    digest_type = -1;
+    digest_type = SUDO_DIGEST_INVALID;
     prev_state = INITIAL;
     BEGIN INITIAL;