diff --git a/internal/output/output.go b/internal/output/output.go
index 4b94a3b..edbe98e 100644
--- a/internal/output/output.go
+++ b/internal/output/output.go
@@ -219,7 +219,13 @@ func formatCard(card *a2a.AgentCard) string {
 	if len(card.SupportedInterfaces) > 0 {
 		sb.WriteString("Interfaces:\n")
 		for _, iface := range card.SupportedInterfaces {
-			fmt.Fprintf(&sb, "  %-12s %s\n", iface.ProtocolBinding, iface.URL)
+			// Include protocol version so cards that expose more than one
+			// (e.g. 0.3 and 1.0 JSONRPC) are distinguishable (#88).
+			if iface.ProtocolVersion != "" {
+				fmt.Fprintf(&sb, "  %-12s %-6s %s\n", iface.ProtocolBinding, iface.ProtocolVersion, iface.URL)
+			} else {
+				fmt.Fprintf(&sb, "  %-12s %s\n", iface.ProtocolBinding, iface.URL)
+			}
 		}
 	}
 
diff --git a/internal/output/output_test.go b/internal/output/output_test.go
index d41a1f8..0387134 100644
--- a/internal/output/output_test.go
+++ b/internal/output/output_test.go
@@ -16,6 +16,7 @@ package output
 
 import (
 	"bytes"
+	"strings"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
@@ -111,3 +112,21 @@ func TestMessageTextFileParts(t *testing.T) {
 		})
 	}
 }
+
+func TestFormatCard_InterfacesIncludeProtocolVersion(t *testing.T) {
+	card := &a2a.AgentCard{
+		Name:    "Example Agent",
+		Version: "1.0.0",
+		SupportedInterfaces: []*a2a.AgentInterface{
+			{URL: "https://example.com/a2a/v03", ProtocolBinding: a2a.TransportProtocolJSONRPC, ProtocolVersion: "0.3"},
+			{URL: "https://example.com/a2a", ProtocolBinding: a2a.TransportProtocolJSONRPC, ProtocolVersion: a2a.Version},
+		},
+	}
+	out := formatCard(card)
+	if !strings.Contains(out, "JSONRPC") || !strings.Contains(out, "0.3") || !strings.Contains(out, "1.0") {
+		t.Fatalf("Interfaces output missing protocol versions:\n%s", out)
+	}
+	if !strings.Contains(out, "https://example.com/a2a/v03") {
+		t.Fatalf("missing interface URL:\n%s", out)
+	}
+}