diff --git a/internal/version/version_test.go b/internal/version/version_test.go
new file mode 100644
index 0000000..dbf052d
--- /dev/null
+++ b/internal/version/version_test.go
@@ -0,0 +1,102 @@
+package version
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestVersion(t *testing.T) {
+	v := Version()
+	
+	// Check that version is not empty
+	if v == "" {
+		t.Error("Version() returned empty string")
+	}
+
+	// Check format (should be X.Y.Z)
+	parts := strings.Split(v, ".")
+	if len(parts) != 3 {
+		t.Errorf("Version() = %q; expected format X.Y.Z", v)
+	}
+
+	// Verify it matches the constants
+	expected := "1.0.0"
+	if v != expected {
+		t.Errorf("Version() = %q; want %q", v, expected)
+	}
+}
+
+func TestFullVersion(t *testing.T) {
+	fv := FullVersion()
+	
+	// Check that full version is not empty
+	if fv == "" {
+		t.Error("FullVersion() returned empty string")
+	}
+
+	// Check that it contains "Zipprine"
+	if !strings.Contains(fv, "Zipprine") {
+		t.Errorf("FullVersion() = %q; expected to contain 'Zipprine'", fv)
+	}
+
+	// Check that it contains the version
+	if !strings.Contains(fv, Version()) {
+		t.Errorf("FullVersion() = %q; expected to contain version %q", fv, Version())
+	}
+
+	// Verify exact format
+	expected := "Zipprine v1.0.0"
+	if fv != expected {
+		t.Errorf("FullVersion() = %q; want %q", fv, expected)
+	}
+}
+
+func TestVersionConstants(t *testing.T) {
+	// Test that constants are set correctly
+	if Major != 1 {
+		t.Errorf("Major = %d; want 1", Major)
+	}
+	if Minor != 0 {
+		t.Errorf("Minor = %d; want 0", Minor)
+	}
+	if Patch != 0 {
+		t.Errorf("Patch = %d; want 0", Patch)
+	}
+}
+
+func TestVersionFormat(t *testing.T) {
+	// Test that version follows semantic versioning
+	v := Version()
+	
+	// Should not contain spaces
+	if strings.Contains(v, " ") {
+		t.Errorf("Version() contains spaces: %q", v)
+	}
+
+	// Should not contain 'v' prefix
+	if strings.HasPrefix(v, "v") {
+		t.Errorf("Version() should not have 'v' prefix: %q", v)
+	}
+
+	// Should be numeric with dots
+	for i, c := range v {
+		if c != '.' && (c < '0' || c > '9') {
+			t.Errorf("Version() contains non-numeric character at position %d: %q", i, v)
+		}
+	}
+}
+
+func TestFullVersionFormat(t *testing.T) {
+	fv := FullVersion()
+	
+	// Should start with "Zipprine v"
+	expectedPrefix := "Zipprine v"
+	if !strings.HasPrefix(fv, expectedPrefix) {
+		t.Errorf("FullVersion() should start with %q, got %q", expectedPrefix, fv)
+	}
+
+	// Should end with version number
+	if !strings.HasSuffix(fv, Version()) {
+		t.Errorf("FullVersion() should end with version %q, got %q", Version(), fv)
+	}
+}