diff --git a/dlls/opcservices/factory.c b/dlls/opcservices/factory.c
index 7d72b39b7bc..0c16cc25012 100644
--- a/dlls/opcservices/factory.c
+++ b/dlls/opcservices/factory.c
@@ -309,9 +309,11 @@ static ULONG WINAPI opc_factory_Release(IOpcFactory *iface)
 
 static HRESULT WINAPI opc_factory_CreatePackageRootUri(IOpcFactory *iface, IOpcUri **uri)
 {
-    FIXME("iface %p, uri %p stub!\n", iface, uri);
+    static const WCHAR rootW[] = {'/',0};
 
-    return E_NOTIMPL;
+    TRACE("iface %p, uri %p.\n", iface, uri);
+
+    return opc_uri_create(rootW, uri);
 }
 
 static HRESULT WINAPI opc_factory_CreatePartUri(IOpcFactory *iface, LPCWSTR uri, IOpcPartUri **part_uri)
diff --git a/dlls/opcservices/opc_private.h b/dlls/opcservices/opc_private.h
index 30bcb0090c4..80b1e954b71 100644
--- a/dlls/opcservices/opc_private.h
+++ b/dlls/opcservices/opc_private.h
@@ -47,3 +47,4 @@ static inline BOOL opc_array_reserve(void **elements, size_t *capacity, size_t c
 
 extern HRESULT opc_package_create(IOpcPackage **package) DECLSPEC_HIDDEN;
 extern HRESULT opc_part_uri_create(const WCHAR *uri, IOpcPartUri **part_uri) DECLSPEC_HIDDEN;
+extern HRESULT opc_uri_create(const WCHAR *uri, IOpcUri **opc_uri) DECLSPEC_HIDDEN;
diff --git a/dlls/opcservices/tests/Makefile.in b/dlls/opcservices/tests/Makefile.in
index 202bf87d688..4fa222e9273 100644
--- a/dlls/opcservices/tests/Makefile.in
+++ b/dlls/opcservices/tests/Makefile.in
@@ -1,5 +1,5 @@
 TESTDLL = opcservices.dll
-IMPORTS = ole32 urlmon
+IMPORTS = ole32 urlmon oleaut32
 
 C_SRCS = \
 	opcservices.c
diff --git a/dlls/opcservices/tests/opcservices.c b/dlls/opcservices/tests/opcservices.c
index 28507162c73..9af7aa49b96 100644
--- a/dlls/opcservices/tests/opcservices.c
+++ b/dlls/opcservices/tests/opcservices.c
@@ -210,14 +210,18 @@ static void test_relationship(void)
     static const WCHAR absoluteW[] = {'f','i','l','e',':','/','/','h','o','s','t','/','f','i','l','e','.','t','x','t',0};
     static const WCHAR targetW[] = {'t','a','r','g','e','t',0};
     static const WCHAR typeW[] = {'t','y','p','e',0};
+    static const WCHAR rootW[] = {'/',0};
     IUri *target_uri, *target_uri2, *uri;
     IOpcRelationshipSet *rels;
     IOpcRelationship *rel;
     IOpcFactory *factory;
     IOpcPackage *package;
+    IOpcUri *source_uri;
+    IUnknown *unk;
     DWORD mode;
     HRESULT hr;
     WCHAR *id;
+    BSTR str;
 
     factory = create_factory();
 
@@ -267,6 +271,23 @@ todo_wine
     ok(SUCCEEDED(hr), "Failed to get target mode, hr %#x.\n", hr);
     ok(mode == OPC_URI_TARGET_MODE_INTERNAL, "Unexpected mode %d.\n", mode);
 
+    /* Source uri */
+    hr = IOpcRelationship_GetSourceUri(rel, &source_uri);
+todo_wine
+    ok(SUCCEEDED(hr), "Failed to get source uri, hr %#x.\n", hr);
+
+    hr = IOpcUri_QueryInterface(source_uri, &IID_IOpcPartUri, (void **)&unk);
+    ok(hr == E_NOINTERFACE, "Unexpected hr %#x.\n", hr);
+
+    str = NULL;
+    hr = IOpcUri_GetRawUri(source_uri, &str);
+    ok(SUCCEEDED(hr), "Failed to get raw uri, hr %#x.\n", hr);
+todo_wine
+    ok(!lstrcmpW(rootW, str), "Unexpected uri %s.\n", wine_dbgstr_w(str));
+    SysFreeString(str);
+
+    IOpcUri_Release(source_uri);
+
     IOpcRelationship_Release(rel);
 
     IOpcRelationshipSet_Release(rels);
diff --git a/dlls/opcservices/uri.c b/dlls/opcservices/uri.c
index 60881e865e6..651c2e38f07 100644
--- a/dlls/opcservices/uri.c
+++ b/dlls/opcservices/uri.c
@@ -32,6 +32,7 @@ struct opc_uri
 {
     IOpcPartUri IOpcPartUri_iface;
     LONG refcount;
+    BOOL is_part_uri;
 };
 
 static inline struct opc_uri *impl_from_IOpcPartUri(IOpcPartUri *iface)
@@ -41,9 +42,13 @@ static inline struct opc_uri *impl_from_IOpcPartUri(IOpcPartUri *iface)
 
 static HRESULT WINAPI opc_uri_QueryInterface(IOpcPartUri *iface, REFIID iid, void **out)
 {
+    struct opc_uri *uri = impl_from_IOpcPartUri(iface);
+
     TRACE("iface %p, iid %s, out %p.\n", iface, debugstr_guid(iid), out);
 
-    if (IsEqualIID(iid, &IID_IOpcPartUri) ||
+    if ((uri->is_part_uri && IsEqualIID(iid, &IID_IOpcPartUri)) ||
+            IsEqualIID(iid, &IID_IOpcUri) ||
+            IsEqualIID(iid, &IID_IUri) ||
             IsEqualIID(iid, &IID_IUnknown))
     {
         *out = iface;
@@ -348,8 +353,24 @@ HRESULT opc_part_uri_create(const WCHAR *str, IOpcPartUri **out)
 
     uri->IOpcPartUri_iface.lpVtbl = &opc_part_uri_vtbl;
     uri->refcount = 1;
+    uri->is_part_uri = TRUE;
 
     *out = &uri->IOpcPartUri_iface;
     TRACE("Created part uri %p.\n", *out);
     return S_OK;
 }
+
+HRESULT opc_uri_create(const WCHAR *str, IOpcUri **out)
+{
+    struct opc_uri *uri;
+
+    if (!(uri = heap_alloc_zero(sizeof(*uri))))
+        return E_OUTOFMEMORY;
+
+    uri->IOpcPartUri_iface.lpVtbl = &opc_part_uri_vtbl;
+    uri->refcount = 1;
+
+    *out = (IOpcUri *)&uri->IOpcPartUri_iface;
+    TRACE("Created part uri %p.\n", *out);
+    return S_OK;
+}