diff --git a/parameters/validate_security.go b/parameters/validate_security.go
index e5ce0989..53492b45 100644
--- a/parameters/validate_security.go
+++ b/parameters/validate_security.go
@@ -124,24 +124,37 @@ func (v *paramValidator) validateHTTPSecurityScheme(
 	request *http.Request,
 	pathValue string,
 ) (bool, []*errors.ValidationError) {
-	switch strings.ToLower(secScheme.Scheme) {
-	case "basic", "bearer", "digest":
-		if request.Header.Get("Authorization") == "" {
-			validationErrors := []*errors.ValidationError{
-				{
-					Message:           fmt.Sprintf("Authorization header for '%s' scheme", secScheme.Scheme),
-					Reason:            "Authorization header was not found",
-					ValidationType:    helpers.SecurityValidation,
-					ValidationSubType: secScheme.Scheme,
-					SpecLine:          sec.GoLow().Requirements.ValueNode.Line,
-					SpecCol:           sec.GoLow().Requirements.ValueNode.Column,
-					HowToFix:          "Add an 'Authorization' header to this request",
-				},
-			}
-			errors.PopulateValidationErrors(validationErrors, request, pathValue)
-			return false, validationErrors
+	authorizationHeader := request.Header.Get("Authorization")
+	if authorizationHeader == "" {
+		validationErrors := []*errors.ValidationError{
+			{
+				Message:           fmt.Sprintf("Authorization header for '%s' scheme", secScheme.Scheme),
+				Reason:            "Authorization header was not found",
+				ValidationType:    helpers.SecurityValidation,
+				ValidationSubType: secScheme.Scheme,
+				SpecLine:          sec.GoLow().Requirements.ValueNode.Line,
+				SpecCol:           sec.GoLow().Requirements.ValueNode.Column,
+				HowToFix:          "Add an 'Authorization' header to this request",
+			},
 		}
-		return true, nil
+		errors.PopulateValidationErrors(validationErrors, request, pathValue)
+		return false, validationErrors
+	}
+	if len(authorizationHeader) < len(secScheme.Scheme) || !strings.EqualFold(authorizationHeader[:len(secScheme.Scheme)], secScheme.Scheme) {
+		validationErrors := []*errors.ValidationError{
+			{
+				Message:           fmt.Sprintf("Authorization header scheme '%s' mismatch", secScheme.Scheme),
+				Reason:            "Authorization header had incorrect scheme",
+				ValidationType:    helpers.SecurityValidation,
+				ValidationSubType: secScheme.Scheme,
+				SpecLine:          sec.GoLow().Requirements.ValueNode.Line,
+				SpecCol:           sec.GoLow().Requirements.ValueNode.Column,
+				HowToFix: fmt.Sprintf("Use the scheme '%s' in the Authorization header "+
+					"for this request", secScheme.Scheme),
+			},
+		}
+		errors.PopulateValidationErrors(validationErrors, request, pathValue)
+		return false, validationErrors
 	}
 	return true, nil
 }
diff --git a/parameters/validate_security_test.go b/parameters/validate_security_test.go
index 8b90212a..78d9ead5 100644
--- a/parameters/validate_security_test.go
+++ b/parameters/validate_security_test.go
@@ -998,8 +998,8 @@ components:
 	assert.Empty(t, errors)
 }
 
-func TestParamValidator_ValidateSecurity_UnknownHTTPScheme(t *testing.T) {
-	// Test custom HTTP scheme - unknown to our validator, should pass through (not fail)
+func TestParamValidator_ValidateSecurity_CustomHTTPScheme(t *testing.T) {
+	// Test custom HTTP scheme - should pass with correct scheme in header
 	spec := `openapi: 3.1.0
 paths:
   /products:
@@ -1017,8 +1017,9 @@ components:
 	m, _ := doc.BuildV3Model()
 	v := NewParameterValidator(&m.Model)
 
-	// Request with no auth - should pass because custom scheme is not validated
+	// Request with custom auth header - should pass
 	request, _ := http.NewRequest(http.MethodGet, "https://things.com/products", nil)
+	request.Header.Add("Authorization", "Custom dXNlcjpwYXNz")
 
 	valid, errors := v.ValidateSecurity(request)
 	assert.True(t, valid)
@@ -1053,3 +1054,32 @@ components:
 	assert.True(t, valid)
 	assert.Empty(t, errors)
 }
+
+func TestParamValidator_ValidateSecurity_HTTPScheme_Mismatch(t *testing.T) {
+	// Test http scheme with mismatch in header: should return errors
+	spec := `openapi: 3.1.0
+paths:
+  /products:
+    get:
+      security:
+        - CustomAuth: []
+components:
+  securitySchemes:
+    CustomAuth:
+      type: http
+      scheme: custom
+`
+
+	doc, _ := libopenapi.NewDocument([]byte(spec))
+	m, _ := doc.BuildV3Model()
+	v := NewParameterValidator(&m.Model)
+
+	// Request with auth header - should fail as header scheme is incorrect
+	request, _ := http.NewRequest(http.MethodGet, "https://things.com/products", nil)
+	request.Header.Add("Authorization", "Basic dXNlcjpwYXNz")
+
+	valid, errors := v.ValidateSecurity(request)
+	assert.False(t, valid)
+	assert.Len(t, errors, 1)
+	assert.Contains(t, errors[0].Message, "Authorization header scheme 'custom' mismatch")
+}