diff --git a/mock/mock.go b/mock/mock.go
index 920a87a..41257fb 100644
--- a/mock/mock.go
+++ b/mock/mock.go
@@ -505,11 +505,12 @@ func (m *Mock) MethodCalled(methodName string, arguments ...interface{}) Argumen
 		m.mutex.Unlock()
 
 		if closestCall != nil {
-			m.fail("\n\nmock: Unexpected Method Call\n-----------------------------\n\n%s\n\nThe closest call I have is: \n\n%s\n\n%s\nDiff: %s",
+			m.fail("\n\nmock: Unexpected Method Call\n-----------------------------\n\n%s\n\nThe closest call I have is: \n\n%s\n\n%s\nDiff: %s\nat: %s\n",
 				callString(methodName, arguments, true),
 				callString(methodName, closestCall.Arguments, true),
 				diffArguments(closestCall.Arguments, arguments),
 				strings.TrimSpace(mismatch),
+				assert.CallerInfo(),
 			)
 		} else {
 			m.fail("\nassert: mock: I don't know what to return because the method call was unexpected.\n\tEither do Mock.On(\"%s\").Return(...) first, or remove the %s() call.\n\tThis method was unexpected:\n\t\t%s\n\tat: %s", methodName, methodName, callString(methodName, arguments, true), assert.CallerInfo())
@@ -825,21 +826,20 @@ func IsType(t interface{}) *IsTypeArgument {
 	return &IsTypeArgument{t: reflect.TypeOf(t)}
 }
 
-// FunctionalOptionsArgument is a struct that contains the type and value of an functional option argument
-// for use when type checking.
+// FunctionalOptionsArgument contains a list of functional options arguments
+// expected for use when matching a list of arguments.
 type FunctionalOptionsArgument struct {
-	value interface{}
+	values []interface{}
 }
 
 // String returns the string representation of FunctionalOptionsArgument
 func (f *FunctionalOptionsArgument) String() string {
 	var name string
-	tValue := reflect.ValueOf(f.value)
-	if tValue.Len() > 0 {
-		name = "[]" + reflect.TypeOf(tValue.Index(0).Interface()).String()
+	if len(f.values) > 0 {
+		name = "[]" + reflect.TypeOf(f.values[0]).String()
 	}
 
-	return strings.Replace(fmt.Sprintf("%#v", f.value), "[]interface {}", name, 1)
+	return strings.Replace(fmt.Sprintf("%#v", f.values), "[]interface {}", name, 1)
 }
 
 // FunctionalOptions returns an [FunctionalOptionsArgument] object containing
@@ -847,10 +847,10 @@ func (f *FunctionalOptionsArgument) String() string {
 //
 // For example:
 //
-//	Assert(t, FunctionalOptions(foo.Opt1("strValue"), foo.Opt2(613)))
-func FunctionalOptions(value ...interface{}) *FunctionalOptionsArgument {
+//	args.Assert(t, FunctionalOptions(foo.Opt1("strValue"), foo.Opt2(613)))
+func FunctionalOptions(values ...interface{}) *FunctionalOptionsArgument {
 	return &FunctionalOptionsArgument{
-		value: value,
+		values: values,
 	}
 }
 
@@ -1004,20 +1004,17 @@ func (args Arguments) Diff(objects []interface{}) (string, int) {
 					output = fmt.Sprintf("%s\t%d: FAIL:  type %s != type %s - %s\n", output, i, expected.t.Name(), actualT.Name(), actualFmt)
 				}
 			case *FunctionalOptionsArgument:
-				t := expected.value
-
 				var name string
-				tValue := reflect.ValueOf(t)
-				if tValue.Len() > 0 {
-					name = "[]" + reflect.TypeOf(tValue.Index(0).Interface()).String()
+				if len(expected.values) > 0 {
+					name = "[]" + reflect.TypeOf(expected.values[0]).String()
 				}
 
-				tName := reflect.TypeOf(t).Name()
-				if name != reflect.TypeOf(actual).String() && tValue.Len() != 0 {
+				const tName = "[]interface{}"
+				if name != reflect.TypeOf(actual).String() && len(expected.values) != 0 {
 					differences++
 					output = fmt.Sprintf("%s\t%d: FAIL:  type %s != type %s - %s\n", output, i, tName, reflect.TypeOf(actual).Name(), actualFmt)
 				} else {
-					if ef, af := assertOpts(t, actual); ef == "" && af == "" {
+					if ef, af := assertOpts(expected.values, actual); ef == "" && af == "" {
 						// match
 						output = fmt.Sprintf("%s\t%d: PASS:  %s == %s\n", output, i, tName, tName)
 					} else {
diff --git a/mock/mock_test.go b/mock/mock_test.go
index 4878b67..d286867 100644
--- a/mock/mock_test.go
+++ b/mock/mock_test.go
@@ -2030,7 +2030,7 @@ func TestArgumentMatcherToPrintMismatch(t *testing.T) {
 	defer func() {
 		if r := recover(); r != nil {
 			matchingExp := regexp.MustCompile(
-				`\s+mock: Unexpected Method Call\s+-*\s+GetTime\(int\)\s+0: 1\s+The closest call I have is:\s+GetTime\(mock.argumentMatcher\)\s+0: mock.argumentMatcher\{.*?\}\s+Diff:.*\(int=1\) not matched by func\(int\) bool`)
+				`\s+mock: Unexpected Method Call\s+-*\s+GetTime\(int\)\s+0: 1\s+The closest call I have is:\s+GetTime\(mock.argumentMatcher\)\s+0: mock.argumentMatcher\{.*?\}\s+Diff:.*\(int=1\) not matched by func\(int\) bool\nat: \[[^\]]+mock\/mock_test.go`)
 			assert.Regexp(t, matchingExp, r)
 		}
 	}()
@@ -2047,7 +2047,7 @@ func TestArgumentMatcherToPrintMismatchWithReferenceType(t *testing.T) {
 	defer func() {
 		if r := recover(); r != nil {
 			matchingExp := regexp.MustCompile(
-				`\s+mock: Unexpected Method Call\s+-*\s+GetTimes\(\[\]int\)\s+0: \[\]int\{1\}\s+The closest call I have is:\s+GetTimes\(mock.argumentMatcher\)\s+0: mock.argumentMatcher\{.*?\}\s+Diff:.*\(\[\]int=\[1\]\) not matched by func\(\[\]int\) bool`)
+				`\s+mock: Unexpected Method Call\s+-*\s+GetTimes\(\[\]int\)\s+0: \[\]int\{1\}\s+The closest call I have is:\s+GetTimes\(mock.argumentMatcher\)\s+0: mock.argumentMatcher\{.*?\}\s+Diff:.*\(\[\]int=\[1\]\) not matched by func\(\[\]int\) bool\nat: \[[^\]]+mock\/mock_test.go`)
 			assert.Regexp(t, matchingExp, r)
 		}
 	}()
@@ -2078,7 +2078,7 @@ func TestClosestCallMismatchedArgumentInformationShowsTheClosest(t *testing.T) {
 func TestClosestCallFavorsFirstMock(t *testing.T) {
 	defer func() {
 		if r := recover(); r != nil {
-			diffRegExp := `Difference found in argument 0:\s+--- Expected\s+\+\+\+ Actual\s+@@ -2,4 \+2,4 @@\s+\(bool\) true,\s+- \(bool\) true,\s+- \(bool\) true\s+\+ \(bool\) false,\s+\+ \(bool\) false\s+}\s+`
+			diffRegExp := `Difference found in argument 0:\s+--- Expected\s+\+\+\+ Actual\s+@@ -2,4 \+2,4 @@\s+\(bool\) true,\s+- \(bool\) true,\s+- \(bool\) true\s+\+ \(bool\) false,\s+\+ \(bool\) false\s+}\s+Diff: 0: FAIL:  \(\[\]bool=\[(true\s?|false\s?){3}]\) != \(\[\]bool=\[(true\s?|false\s?){3}\]\)`
 			matchingExp := regexp.MustCompile(unexpectedCallRegex(`TheExampleMethod7([]bool)`, `0: \[\]bool{true, false, false}`, `0: \[\]bool{true, true, true}`, diffRegExp))
 			assert.Regexp(t, matchingExp, r)
 		}
@@ -2094,7 +2094,7 @@ func TestClosestCallFavorsFirstMock(t *testing.T) {
 func TestClosestCallUsesRepeatabilityToFindClosest(t *testing.T) {
 	defer func() {
 		if r := recover(); r != nil {
-			diffRegExp := `Difference found in argument 0:\s+--- Expected\s+\+\+\+ Actual\s+@@ -1,4 \+1,4 @@\s+\(\[\]bool\) \(len=3\) {\s+- \(bool\) false,\s+- \(bool\) false,\s+\+ \(bool\) true,\s+\+ \(bool\) true,\s+\(bool\) false\s+`
+			diffRegExp := `Difference found in argument 0:\s+--- Expected\s+\+\+\+ Actual\s+@@ -1,4 \+1,4 @@\s+\(\[\]bool\) \(len=3\) {\s+- \(bool\) false,\s+- \(bool\) false,\s+\+ \(bool\) true,\s+\+ \(bool\) true,\s+\(bool\) false\s+Diff: 0: FAIL:  \(\[\]bool=\[(true\s?|false\s?){3}]\) != \(\[\]bool=\[(true\s?|false\s?){3}\]\)`
 			matchingExp := regexp.MustCompile(unexpectedCallRegex(`TheExampleMethod7([]bool)`, `0: \[\]bool{true, true, false}`, `0: \[\]bool{false, false, false}`, diffRegExp))
 			assert.Regexp(t, matchingExp, r)
 		}
@@ -2151,7 +2151,7 @@ func Test_isBetterMatchThanReturnsFalseIfRepeatabilityIsLessThanOrEqualToOther(t
 
 func unexpectedCallRegex(method, calledArg, expectedArg, diff string) string {
 	rMethod := regexp.QuoteMeta(method)
-	return fmt.Sprintf(`\s+mock: Unexpected Method Call\s+-*\s+%s\s+%s\s+The closest call I have is:\s+%s\s+%s\s+%s`,
+	return fmt.Sprintf(`\s+mock: Unexpected Method Call\s+-*\s+%s\s+%s\s+The closest call I have is:\s+%s\s+%s\s+%s\nat: \[[^\]]+mock\/mock_test.go`,
 		rMethod, calledArg, rMethod, expectedArg, diff)
 }