diff --git a/common.c b/common.c
index 9aeb747..61a953c 100644
--- a/common.c
+++ b/common.c
@@ -250,3 +250,17 @@ char *strmov(char *dest, const char *src) {
     ;
   return dest-1;
 }
+
+/* New database and user names may only use these characters in their
+   identifier */
+const char name_validchars[] =
+  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-";
+
+/* Returns true if dbname contains only characters in name_validchars. */
+int name_isclean(char* name) {
+  int reallen, cleanlen;
+  reallen = strlen(name);
+  cleanlen = strspn(name, name_validchars);
+  return (reallen == cleanlen);
+}
+
diff --git a/mysql-admutils.h b/mysql-admutils.h
index 618e681..1ee0cdc 100644
--- a/mysql-admutils.h
+++ b/mysql-admutils.h
@@ -36,6 +36,7 @@ read_config_file(void);
 /* same as strcpy, but returns a pointer to the end of dest instead of start */
 extern char *strmov(char *, const char *);
 
+extern int name_isclean(char*);
 
 #ifdef _mysql_h
 
diff --git a/mysql-dbadm.c b/mysql-dbadm.c
index 38eba14..bc21dc6 100644
--- a/mysql-dbadm.c
+++ b/mysql-dbadm.c
@@ -19,19 +19,6 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-/* New database names may only use these characters in their identifier */
-const char dbname_validchars[] =
-  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_-";
-
-
-/* Returns true if dbname contains only characters in dbname_validchars. */
-int dbname_isclean(char* dbname) {
-  int reallen, cleanlen;
-  reallen = strlen(dbname);
-  cleanlen = strspn(dbname, dbname_validchars);
-  return (reallen == cleanlen);
-}
-
 char *
 strchr_whitespace(const char *s)
 {
@@ -665,7 +652,7 @@ main(int argc, char *argv[])
       switch (command) {
         case c_create:
         // We only check newly created databases. Many old ("unclean") databases are still in use.
-          if(dbname_isclean(db)) {
+          if(name_isclean(db)) {
             create(&mysql, db);
           } else {
             dberror(NULL, "Database name '%s' contains invalid characters.\n"
@@ -673,7 +660,7 @@ main(int argc, char *argv[])
           }
           break;
         case c_drop:
-          if(dbname_isclean(db)) {
+          if(name_isclean(db)) {
             drop(&mysql, db);
           } else {
             dberror(NULL, "Database name '%s' contains invalid characters.\n"
@@ -681,7 +668,7 @@ main(int argc, char *argv[])
           }
           break;
         case c_editperm:
-          if(dbname_isclean(db)) {
+          if(name_isclean(db)) {
             editperm(&mysql, db);
           } else {
             dberror(NULL, "Database name '%s' contains invalid characters.\n"
@@ -689,7 +676,7 @@ main(int argc, char *argv[])
           }
           break;
         case c_show:
-          if(dbname_isclean(db)) {
+          if(name_isclean(db)) {
             show(&mysql, db);
           } else {
             dberror(NULL, "Database name '%s' contains invalid characters.\n"
diff --git a/mysql-useradm.c b/mysql-useradm.c
index 7ab4a30..bfb3acb 100644
--- a/mysql-useradm.c
+++ b/mysql-useradm.c
@@ -322,16 +322,36 @@ main(int argc, char *argv[])
           switch (command)
             {
             case c_create:
-              create(&mysql, user);
+              if(name_isclean(user)) {
+                create(&mysql, user);
+              } else {
+                dberror(NULL, "User name '%s' contains invalid characters.\n"
+                  "Only A-Z, a-z, 0-9, _ (underscore) and - (dash) permitted. Skipping.", user);
+              }
               break;
             case c_delete:
-              delete(&mysql, user);
+              if(name_isclean(user)) {
+                delete(&mysql, user);
+              } else {
+                dberror(NULL, "User name '%s' contains invalid characters.\n"
+                  "Only A-Z, a-z, 0-9, _ (underscore) and - (dash) permitted. Skipping.", user);
+              }
               break;
             case c_passwd:
-              passwd(&mysql, user);
+              if(name_isclean(user)) {
+                passwd(&mysql, user);
+              } else {
+                dberror(NULL, "User name '%s' contains invalid characters.\n"
+                  "Only A-Z, a-z, 0-9, _ (underscore) and - (dash) permitted. Skipping.", user);
+              }
               break;
             case c_show:
-              show(&mysql, user);
+              if(name_isclean(user)) {
+                show(&mysql, user);
+              } else {
+                dberror(NULL, "User name '%s' contains invalid characters.\n"
+                  "Only A-Z, a-z, 0-9, _ (underscore) and - (dash) permitted. Skipping.", user);
+              }
               break;
             default:
               fprintf(stderr, "This point should never be reached.\n");