diff --git a/DESCRIPTION b/DESCRIPTION
index 0d6a7cba..c1ef4673 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: TwoSampleMR
 Title: Two Sample MR Functions and Interface to MRC Integrative
     Epidemiology Unit OpenGWAS Database
-Version: 0.6.28
+Version: 0.6.29
 Authors@R: c(
     person("Gibran", "Hemani", , "g.hemani@bristol.ac.uk", role = c("aut", "cre"),
            comment = c(ORCID = "0000-0003-0920-1055")),
diff --git a/NEWS.md b/NEWS.md
index 3902f3d3..a57974d8 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,6 +1,12 @@
 # TwoSampleMR v0.6.28
 
-(Release date 2025-12-15)
+(Release date 2025-12-16)
+
+* Skip two tests if the **MendelianRandomization** package is not installed and protected the running of the perform_mr vignette.
+
+# TwoSampleMR v0.6.28
+
+(Release date 2025-12-16)
 
 * Allowed the arguments for `clump_data()` to be specified from `read_exposure_data()` (thanks @al3xjwood).
 * Fixed two function calls in `mr_moe_single()`
diff --git a/tests/testthat/test_otherformats.R b/tests/testthat/test_otherformats.R
index c6f9d35c..95b1272a 100644
--- a/tests/testthat/test_otherformats.R
+++ b/tests/testthat/test_otherformats.R
@@ -6,6 +6,7 @@ load(system.file("extdata", "test_commondata.RData", package = "TwoSampleMR"))
 
 test_that("MRInput", {
   skip_if(getRversion() < '4.4.0') # because MendelianRandomization will not be installed
+  skip_if_not_installed("MendelianRandomization")
   w <- dat_to_MRInput(dat, get_correlations = FALSE)
   expect_true(length(w) == 1)
   expect_true(class(w) == "list")
@@ -18,6 +19,7 @@ test_that("MRInput with cor", {
   skip_if_offline()
   skip_if_offline(host = "api.opengwas.io")
   skip_if(getRversion() < '4.4.0') # because MendelianRandomization will not be installed
+  skip_if_not_installed("MendelianRandomization")
   w <- tryCatch(
     dat_to_MRInput(dat, get_correlations = TRUE)[[1]],
     error = skip("Server issues"),
diff --git a/vignettes/perform_mr.Rmd b/vignettes/perform_mr.Rmd
index e07f9d7d..70f672cb 100644
--- a/vignettes/perform_mr.Rmd
+++ b/vignettes/perform_mr.Rmd
@@ -13,7 +13,7 @@ vignette: >
 ---
 
 ```{r, include=FALSE}
-evalinr44 <- getRversion() >= '4.4.0'
+evalinr44 <- (getRversion() >= '4.4.0') && requireNamespace("MendelianRandomization", quietly = TRUE)
 knitr::opts_chunk$set(
   collapse = TRUE,
   comment = "#>",