diff --git a/src/modules/module_03100.c b/src/modules/module_03100.c
index f5b77a395..7cffab6a6 100644
--- a/src/modules/module_03100.c
+++ b/src/modules/module_03100.c
@@ -84,7 +84,7 @@ int module_hash_decode (MAYBE_UNUSED const hashconfig_t *hashconfig, MAYBE_UNUSE
   token.attr[0]    = TOKEN_ATTR_FIXED_LENGTH
                    | TOKEN_ATTR_VERIFY_HEX;
 
-  token.len_min[1] = 0;
+  token.len_min[1] = 1;
   token.len_max[1] = 30;
   token.attr[1]    = TOKEN_ATTR_VERIFY_LENGTH;
 
diff --git a/tools/test_modules/m03100.pm b/tools/test_modules/m03100.pm
index 515103df7..bf87c8fd7 100644
--- a/tools/test_modules/m03100.pm
+++ b/tools/test_modules/m03100.pm
@@ -10,7 +10,7 @@ use warnings;
 
 use Crypt::CBC;
 
-sub module_constraints { [[-1, -1], [-1, -1], [0, 30], [0, 30], [-1, -1]] }
+sub module_constraints { [[-1, -1], [-1, -1], [0, 30], [1, 30], [-1, -1]] }
 
 sub module_generate_hash
 {