diff --git a/Makefile b/Makefile
index b7e5f99..4e0b9e5 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ ifeq (${KERNEL},Linux)
 	GOFLAGS ?= -buildmode=pie
 endif
 
-GO_LDFLAGS += -w -s -X main.version=${VERSION}
+GO_LDFLAGS += -w -s -X github.com/cloudflare/origin-ca-issuer/internal/version.Version=${VERSION}
 GOFLAGS += -v
 
 export CGO_ENABLED
diff --git a/internal/cfapi/cfapi.go b/internal/cfapi/cfapi.go
index d803613..7e15d9b 100644
--- a/internal/cfapi/cfapi.go
+++ b/internal/cfapi/cfapi.go
@@ -8,6 +8,8 @@ import (
 	"net/http"
 	"net/url"
 	"time"
+
+	"github.com/cloudflare/origin-ca-issuer/internal/version"
 )
 
 type Interface interface {
@@ -121,7 +123,7 @@ func (c *Client) Sign(ctx context.Context, req *SignRequest) (*SignResponse, err
 		return nil, err
 	}
 
-	r.Header.Add("User-Agent", "github.com/cloudflare/origin-ca-issuer")
+	r.Header.Add("User-Agent", "origin-ca-issuer/"+version.Version)
 
 	if c.serviceKey != nil {
 		r.Header.Add("X-Auth-User-Service-Key", string(c.serviceKey))
diff --git a/internal/version/version.go b/internal/version/version.go
new file mode 100644
index 0000000..415100d
--- /dev/null
+++ b/internal/version/version.go
@@ -0,0 +1,3 @@
+package version
+
+var Version = "0.0.0"
diff --git a/pkgs/controllers/testdata/database-failure.yaml b/pkgs/controllers/testdata/database-failure.yaml
index 3188476..29bf93a 100644
--- a/pkgs/controllers/testdata/database-failure.yaml
+++ b/pkgs/controllers/testdata/database-failure.yaml
@@ -16,7 +16,7 @@ interactions:
           form: {}
           headers:
               User-Agent:
-                  - github.com/cloudflare/origin-ca-issuer
+                  - origin-ca-issuer/0.0.0
               X-Auth-User-Service-Key:
                   - djEuMC0weDAwQkFCMTBD
           url: https://api.cloudflare.com/client/v4/certificates
diff --git a/pkgs/controllers/testdata/working.yaml b/pkgs/controllers/testdata/working.yaml
index 83dbd45..a19bfd3 100644
--- a/pkgs/controllers/testdata/working.yaml
+++ b/pkgs/controllers/testdata/working.yaml
@@ -16,7 +16,7 @@ interactions:
       form: {}
       headers:
         User-Agent:
-          - github.com/cloudflare/origin-ca-issuer
+          - origin-ca-issuer/0.0.0
         X-Auth-User-Service-Key:
           - djEuMC0weDAwQkFCMTBD
       url: https://api.cloudflare.com/client/v4/certificates
@@ -62,7 +62,7 @@ interactions:
       form: {}
       headers:
         User-Agent:
-          - github.com/cloudflare/origin-ca-issuer
+          - origin-ca-issuer/0.0.0
         Authorization:
           - Bearer api-token
       url: https://api.cloudflare.com/client/v4/certificates