diff --git a/R/install_packages.R b/R/install_packages.R
index df4dea72..b893d034 100644
--- a/R/install_packages.R
+++ b/R/install_packages.R
@@ -89,7 +89,7 @@ install_packages_cran <- function(packages, instructions=FALSE) {
     return(character(0))
   }
   if (instructions) {
-    sprintf("install.packages(%s)",
+    sprintf("install.packages(c(%s))",
             paste(dquote(packages), collapse=", "))
   } else {
     ## This is super annoying but means that we'll hopefully get
diff --git a/tests/testthat/test-install-packages.R b/tests/testthat/test-install-packages.R
index b8fded4b..4f8770aa 100644
--- a/tests/testthat/test-install-packages.R
+++ b/tests/testthat/test-install-packages.R
@@ -15,7 +15,7 @@ test_that("sources", {
 
 test_that("install_packages", {
   extras <- read_remake_packages("remake_sources.yml")
-  cmp_devtools_cran <- 'install.packages("devtools")'
+  cmp_devtools_cran <- 'install.packages(c("devtools"))'
   expect_equal(install_packages("devtools", TRUE, FALSE, extras),
                cmp_devtools_cran)
   expect_equal(install_packages("sowsear", TRUE, FALSE, extras),
@@ -57,7 +57,7 @@ test_that("loading a remakefile with a missing package", {
   cleanup()
   obj <- suppressWarnings(remake("remake_missing_package.yml"))
   expect_error(.remake_initialize_packages(obj),
-               'install.packages("nosuchpackage")', fixed=TRUE)
+               'install.packages(c("nosuchpackage"))', fixed=TRUE)
 
   skip_unless_set("REMAKE_TEST_INSTALL_PACKAGES")
   expect_warning(m <- remake("remake_missing_package.yml", allow_cache=FALSE),