diff --git a/src/list_validator.erl b/src/list_validator.erl
index 04bf1ff..275ecaf 100644
--- a/src/list_validator.erl
+++ b/src/list_validator.erl
@@ -43,7 +43,9 @@ validate(Term, {item, Format}, Validators) ->
                 valid ->
                     Accumulator;
                 {invalid, Reason} ->
-                    [{Index, Reason}|Accumulator]
+                    [{Index, Reason}|Accumulator];
+                OtherError ->
+                    [{Index, OtherError}|Accumulator]
             end
         end,
         [],
diff --git a/src/map_dynamic_validator.erl b/src/map_dynamic_validator.erl
index 73422eb..7d814f3 100644
--- a/src/map_dynamic_validator.erl
+++ b/src/map_dynamic_validator.erl
@@ -41,7 +41,9 @@ validate(Term, {key, Format}, Validators) ->
             valid ->
                 Accumulator;
             {invalid, Reason} ->
-                [{Key, Reason}|Accumulator]
+                [{Key, Reason}|Accumulator];
+            OtherError ->
+                [{Key, OtherError}|Accumulator]
         end
     end, [], maps:keys(Term)),
     case Result of
@@ -57,7 +59,9 @@ validate(Term, {value, Format}, Validators) ->
             valid ->
                 Accumulator;
             {invalid, Reason} ->
-                [{Key, Reason}|Accumulator]
+                [{Key, Reason}|Accumulator];
+            OtherError ->
+                [{Key, OtherError}|Accumulator]
         end
     end, [], Term),
     case Result of
diff --git a/src/map_validator.erl b/src/map_validator.erl
index 400bdf8..b8e1a0a 100644
--- a/src/map_validator.erl
+++ b/src/map_validator.erl
@@ -27,7 +27,7 @@ pre_validate(Term, Options, _Validators) when is_map(Term) ->
 pre_validate(_Term, _Options, _Validators) ->
     {invalid, not_map}.
 
-validate(Term, {fields, Fields}, Validators) ->
+validate(Term, {fields, Fields}, Validators) when is_list(Fields) ->
     % We first compute the missing fields by iterating over the declared
     % mandatory fields and check if they are all present in the Erlang map.
     % Then we compute the invalid and extra fields by iterating over the fields
@@ -59,7 +59,9 @@ validate(Term, {fields, Fields}, Validators) ->
                                 valid ->
                                     Accumulator;
                                 {invalid, Reason} ->
-                                    {UnexpectedFields, [{Key, Reason}|InvalidFields]}
+                                    {UnexpectedFields, [{Key, Reason}|InvalidFields]};
+                                OtherError ->
+                                    {UnexpectedFields, [{Key, OtherError}|InvalidFields]}
                             end
                     end
                 end,
@@ -79,7 +81,9 @@ validate(Term, {fields, Fields}, Validators) ->
             end;
         _ ->
             {invalid, {missing_fields, MissingFields}}
-    end.
+    end;
+validate(_Term, {fields, _Fields}, _Validators) ->
+    {invalid_option_value, not_list}.
 
 post_validate(_Term, _Validators) ->
     valid.
diff --git a/src/term_validator.erl b/src/term_validator.erl
index 51d584b..2744b3a 100644
--- a/src/term_validator.erl
+++ b/src/term_validator.erl
@@ -153,14 +153,12 @@ has_dynamic_options(_MandatoryOptions, _OptionalOptions) ->
 -spec has_missing_options(options(), [option_name()]) ->
     no | {yes, [option_name()]}.
 has_missing_options(Options, MandatoryOptions) ->
-    % We remove mandatory option one by one if they're present. If there's
-    % remaining mandatory options, then we have missing options.
-    RemainingOptions = lists:dropwhile(fun(Name) ->
-        proplists:is_defined(Name, Options)
+    Missing = lists:filter(fun(Name) ->
+        not proplists:is_defined(Name, Options)
     end, MandatoryOptions),
-    case RemainingOptions of
+    case Missing of
         [] -> no;
-        _ -> {yes, RemainingOptions}
+        _  -> {yes, Missing}
     end.
 
 -spec has_invalid_options(options(), [option_name()]) ->
diff --git a/src/tuple_dynamic_validator.erl b/src/tuple_dynamic_validator.erl
index 92400fb..07d2309 100644
--- a/src/tuple_dynamic_validator.erl
+++ b/src/tuple_dynamic_validator.erl
@@ -43,7 +43,9 @@ validate(Term, {element, Format}, Validators) ->
                 valid ->
                     Accumulator;
                 {invalid, Reason} ->
-                    [{Index, Reason}|Accumulator]
+                    [{Index, Reason}|Accumulator];
+                OtherError ->
+                    [{Index, OtherError}|Accumulator]
             end
         end,
         [],
diff --git a/src/tuple_validator.erl b/src/tuple_validator.erl
index 8ecced5..9a7250b 100644
--- a/src/tuple_validator.erl
+++ b/src/tuple_validator.erl
@@ -39,7 +39,9 @@ validate(Term, {elements, Elements}, Validators) ->
                 valid ->
                     Accumulator;
                 {invalid, Reason} ->
-                    [{Index, Reason}|Accumulator]
+                    [{Index, Reason}|Accumulator];
+                OtherError ->
+                    [{Index, OtherError}|Accumulator]
             end
         end,
         [],
diff --git a/test/map_validator_test.erl b/test/map_validator_test.erl
index 094a7b5..ca83058 100644
--- a/test/map_validator_test.erl
+++ b/test/map_validator_test.erl
@@ -71,3 +71,22 @@ map_validator_fields_test() ->
     true = lists:member({"bar", not_number}, Fields),
 
     ok.
+
+map_validator_options_test() ->
+    UnknownValidatorFormat = {map, [{fields, [
+        {foo, unknown_validator, mandatory}
+    ]}]},
+    {invalid, {fields, [{foo,{no_validator,unknown_validator}}]}} = term_validator:validate(#{
+        foo => true
+    }, UnknownValidatorFormat),
+
+    MissingOptionFormat = {map, []},
+    {missing_options, [fields]} = term_validator:validate(#{}, MissingOptionFormat),
+
+    InvalidOptionsFormat = {map, [{fields, []}, {unknown_option, true}]},
+    {invalid_options, [unknown_option]} = term_validator:validate(#{}, InvalidOptionsFormat),
+
+    InvalidOptionValue = {map, [{fields, atom}]},
+    {invalid_option_value,{fields,atom},not_list} = term_validator:validate(#{}, InvalidOptionValue),
+
+    ok.