diff --git a/DESCRIPTION b/DESCRIPTION
index 98a47a11..9b79541b 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -27,6 +27,7 @@ Imports:
     scales,
     stats
 Suggests:
+    cosinor,
     covr,
     dplyr,
     DT,
diff --git a/R/srr-stats-standards.R b/R/srr-stats-standards.R
index 6ff237d0..d696eabc 100644
--- a/R/srr-stats-standards.R
+++ b/R/srr-stats-standards.R
@@ -149,7 +149,7 @@ NULL
 #' @srrstatsNA {RE4.15}
 #' @srrstatsNA {RE4.16}
 #' @srrstatsNA {RE5.0}
-# @srrstatsNA {RE7.0}
+#' @srrstatsNA {RE7.0}
 #' @srrstatsNA {RE7.0a}
 #' @srrstatsNA {RE7.1}
 #' @srrstatsNA {RE7.1a}
diff --git a/tests/testthat/test-cosinor.R b/tests/testthat/test-cosinor.R
index c5754032..fd0e17fe 100644
--- a/tests/testthat/test-cosinor.R
+++ b/tests/testthat/test-cosinor.R
@@ -6,6 +6,7 @@
 #' @srrstats {G5.5}
 #' @srrstats {G5.4}
 #' @srrstats {G5.4a}
+#' @srrstats {G5.4b}
 #' @srrstats {G5.6}
 #' @srrstats {G5.6a}
 #' @srrstats {G5.6b}
@@ -50,6 +51,7 @@ test_that("model returns accurate parameters", {
         ),
         data = comod
       )
+      cosinor_lm_mod <- cosinor::cosinor.lm(Y ~ time(times) + group + amp.acro(group), data = comod)
     }
   )
   testthat::expect_true(all.equal(
@@ -57,6 +59,17 @@ test_that("model returns accurate parameters", {
     c(1.0030, -0.4966, 2.0122, 0.9948, 3.0115, 0.3175)
   ))
 
+  # test similarity to cosinor::cosinor.lm()
+  comparison_df <- cbind(
+    cosinor_lm_mod$coefficients,
+    object$coefficients
+  )
+
+  comparison_df <- as.data.frame(comparison_df[rownames(comparison_df) != "acr", ])
+  expect_equal(comparison_df$V1, comparison_df$V2, tolerance = 0.1)
+
+
+
   # test another parameter estimation of Gaussian simulated data
   withr::with_seed(
     100,