diff --git a/github.go b/github.go
index 5a5b080..c3f01c3 100644
--- a/github.go
+++ b/github.go
@@ -8,6 +8,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"strings"
 	"time"
 )
 
@@ -101,6 +102,16 @@ func (c *githubClient) withEnterpriseURL(baseURL string) (*githubClient, error)
 		return nil, fmt.Errorf("failed to parse base URL: %w", err)
 	}
 
+	if !strings.HasSuffix(base.Path, "/") {
+		base.Path += "/"
+	}
+
+	if !strings.HasSuffix(base.Path, "/api/v3/") &&
+		!strings.HasPrefix(base.Host, "api.") &&
+		!strings.Contains(base.Host, ".api.") {
+		base.Path += "api/v3/"
+	}
+
 	c.baseURL = base
 
 	return c, nil
diff --git a/github_test.go b/github_test.go
index 1c4f20b..5f02937 100644
--- a/github_test.go
+++ b/github_test.go
@@ -12,33 +12,84 @@ import (
 
 func Test_githubClient_withEnterpriseURL(t *testing.T) {
 	tests := []struct {
-		name    string
-		baseURL string
-		wantErr bool
+		name            string
+		baseURL         string
+		wantErr         bool
+		expectedBaseURL string
 	}{
 		{
-			name:    "valid URL",
-			baseURL: "https://github.example.com",
-			wantErr: false,
+			name:            "valid URL with first subdomain",
+			baseURL:         "https://api.github.example.com",
+			wantErr:         false,
+			expectedBaseURL: "https://api.github.example.com/",
+		},
+		{
+			name:            "valid URL with first subdomain and trailing slash",
+			baseURL:         "https://api.github.example.com/",
+			wantErr:         false,
+			expectedBaseURL: "https://api.github.example.com/",
+		},
+		{
+			name:            "valid URL with second subdomain",
+			baseURL:         "https://ghes.api.example.com",
+			wantErr:         false,
+			expectedBaseURL: "https://ghes.api.example.com/",
+		},
+		{
+			name:            "valid URL with second subdomain and trailing slash",
+			baseURL:         "https://ghes.api.example.com/",
+			wantErr:         false,
+			expectedBaseURL: "https://ghes.api.example.com/",
+		},
+		{
+			name:            "valid URL with path",
+			baseURL:         "https://github.example.com/api/v3",
+			wantErr:         false,
+			expectedBaseURL: "https://github.example.com/api/v3/",
 		},
 		{
-			name:    "invalid URL with control characters",
-			baseURL: "ht\ntp://invalid",
-			wantErr: true,
+			name:            "valid URL with path and trailing slash",
+			baseURL:         "https://github.example.com/api/v3/",
+			wantErr:         false,
+			expectedBaseURL: "https://github.example.com/api/v3/",
 		},
 		{
-			name:    "URL with spaces",
-			baseURL: "http://invalid url with spaces",
-			wantErr: true,
+			name:            "valid URL without path",
+			baseURL:         "https://github.example.com",
+			wantErr:         false,
+			expectedBaseURL: "https://github.example.com/api/v3/",
+		},
+		{
+			name:            "valid URL without path but with trailing slash",
+			baseURL:         "https://github.example.com/",
+			wantErr:         false,
+			expectedBaseURL: "https://github.example.com/api/v3/",
+		},
+		{
+			name:            "invalid URL with control characters",
+			baseURL:         "ht\ntp://invalid",
+			wantErr:         true,
+			expectedBaseURL: "",
+		},
+		{
+			name:            "URL with spaces",
+			baseURL:         "http://invalid url with spaces",
+			wantErr:         true,
+			expectedBaseURL: "",
 		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			client := newGitHubClient(&http.Client{})
-			_, err := client.withEnterpriseURL(tt.baseURL)
+			githubClient, err := client.withEnterpriseURL(tt.baseURL)
+
 			if (err != nil) != tt.wantErr {
-				t.Errorf("withEnterpriseURL() error = %v, wantErr %v", err, tt.wantErr)
+				t.Errorf("withEnterpriseURL(%v) error = %v", tt.baseURL, err)
+			}
+
+			if err == nil && githubClient.baseURL.String() != tt.expectedBaseURL {
+				t.Errorf("withEnterpriseURL(%v) expected = %v, received = %v", tt.baseURL, tt.expectedBaseURL, githubClient.baseURL)
 			}
 		})
 	}