diff --git a/NEWS.md b/NEWS.md
index b2def51a45..d5d4c514d9 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -23,7 +23,8 @@
 * `object_name_linter()` gains a new default style, `"symbols"`, which won't lint all-symbol object names 
   (in particular, that means operator names like `%+%` are skipped; #615, #670, @michaelchirico and @AshesITR)
 * `spaces_inside_linter` ignores spaces preceding trailing comments (#636, @michaelchirico)
-* `T_and_F_symbol_linter` is now part of the default linters (#517, #612, @AshesITR)
+* `T_and_F_symbol_linter` and `semicolon_terminator_linter` are now part of the default linters
+  (#517, #612, #683, #684, @AshesITR)
 * `with_defaults()` no longer duplicates the `lintr_function` class when it is already present (#511, #612, @AshesITR)
 * New `backport_linter()` for detecting mismatched R version dependencies (#506, @MichaelChirico)
 * `paren_brace_linter` and `no_tab_linter` also use more reliable matching (e.g.,
diff --git a/R/tree-utils.R b/R/tree-utils.R
index 9349fea581..e72069953c 100644
--- a/R/tree-utils.R
+++ b/R/tree-utils.R
@@ -22,7 +22,7 @@ component_edges <- function(graph, id) {
     neis <- unlist(graph$adjlist[newv])
     newv <- setdiff(neis, sc)
     sc <- c(sc, newv)
-    if (length(sc) == size) break;
+    if (length(sc) == size) break
     size <- length(sc)
   }
 
diff --git a/R/zzz.R b/R/zzz.R
index bcaf341685..99e3f00f59 100644
--- a/R/zzz.R
+++ b/R/zzz.R
@@ -89,6 +89,7 @@ default_linters <- with_defaults(
   open_curly_linter(),
   paren_brace_linter,
   pipe_continuation_linter,
+  semicolon_terminator_linter(),
   seq_linter,
   single_quotes_linter,
   spaces_inside_linter,
diff --git a/tests/testthat/default_linter_testcode.R b/tests/testthat/default_linter_testcode.R
index fce166aef3..ba7ba7cca1 100644
--- a/tests/testthat/default_linter_testcode.R
+++ b/tests/testthat/default_linter_testcode.R
@@ -39,7 +39,8 @@ message('single_quotes')
 
 # spaces_left_parentheses
 # trailing_whitespace
-y <- 2 +(1:10) 
+# semicolon_terminator
+x <- 42; y <- 2 +(1:10) 
 
 # trailing_blank_lines
 
diff --git a/tests/testthat/dummy_packages/package/R/default_linter_testcode.R b/tests/testthat/dummy_packages/package/R/default_linter_testcode.R
index fce166aef3..ba7ba7cca1 100644
--- a/tests/testthat/dummy_packages/package/R/default_linter_testcode.R
+++ b/tests/testthat/dummy_packages/package/R/default_linter_testcode.R
@@ -39,7 +39,8 @@ message('single_quotes')
 
 # spaces_left_parentheses
 # trailing_whitespace
-y <- 2 +(1:10) 
+# semicolon_terminator
+x <- 42; y <- 2 +(1:10) 
 
 # trailing_blank_lines
 
diff --git a/tests/testthat/dummy_packages/package/data-raw/default_linter_testcode.R b/tests/testthat/dummy_packages/package/data-raw/default_linter_testcode.R
index fce166aef3..ba7ba7cca1 100644
--- a/tests/testthat/dummy_packages/package/data-raw/default_linter_testcode.R
+++ b/tests/testthat/dummy_packages/package/data-raw/default_linter_testcode.R
@@ -39,7 +39,8 @@ message('single_quotes')
 
 # spaces_left_parentheses
 # trailing_whitespace
-y <- 2 +(1:10) 
+# semicolon_terminator
+x <- 42; y <- 2 +(1:10) 
 
 # trailing_blank_lines
 
diff --git a/tests/testthat/dummy_packages/package/inst/data-raw/default_linter_testcode.R b/tests/testthat/dummy_packages/package/inst/data-raw/default_linter_testcode.R
index fce166aef3..ba7ba7cca1 100644
--- a/tests/testthat/dummy_packages/package/inst/data-raw/default_linter_testcode.R
+++ b/tests/testthat/dummy_packages/package/inst/data-raw/default_linter_testcode.R
@@ -39,7 +39,8 @@ message('single_quotes')
 
 # spaces_left_parentheses
 # trailing_whitespace
-y <- 2 +(1:10) 
+# semicolon_terminator
+x <- 42; y <- 2 +(1:10) 
 
 # trailing_blank_lines
 
diff --git a/tests/testthat/test-exclusions.R b/tests/testthat/test-exclusions.R
index 2df58f4750..611f16a9ac 100644
--- a/tests/testthat/test-exclusions.R
+++ b/tests/testthat/test-exclusions.R
@@ -68,7 +68,7 @@ test_that("it returns all lines between start and end", {
 test_that("it ignores exclude coverage lines within start and end", {
   read_settings(NULL)
 
-    t1 <- tempfile()
+  t1 <- tempfile()
   on.exit(unlink(t1))
   writeLines(
     c("this #TeSt_NoLiNt_StArT",
@@ -119,65 +119,97 @@ test_that("it merges two NULL or empty objects as an empty list", {
 })
 
 test_that("it returns the object if the other is NULL", {
-  t1 <- list(); t1[[a]] <- 1:10
+  t1 <- list()
+  t1[[a]] <- 1:10
   expect_equal(normalize_exclusions(c(t1, NULL)), t1)
   expect_equal(normalize_exclusions(c(NULL, t1)), t1)
 })
 
 test_that("it returns the union of two non-overlapping lists", {
-  t1 <- list(); t1[[a]] <- 1:10
-  t2 <- list(); t2[[a]] <- 20:30
-  res <- list(); res[[a]] <- c(1:10, 20:30)
+  t1 <- list()
+  t2 <- list()
+  res <- list()
+  t1[[a]] <- 1:10
+  t2[[a]] <- 20:30
+  res[[a]] <- c(1:10, 20:30)
   expect_equal(normalize_exclusions(c(t1, t2)), res)
 })
 
 test_that("it returns the union of two overlapping lists", {
-  t1 <- list(); t1[[a]] <- 1:10
-  t2 <- list(); t2[[a]] <- 5:15
-  res <- list(); res[[a]] <- 1:15
+  t1 <- list()
+  t2 <- list()
+  res <- list()
+  t1[[a]] <- 1:10
+  t2[[a]] <- 5:15
+  res[[a]] <- 1:15
   expect_equal(normalize_exclusions(c(t1, t2)), res)
 })
 
 test_that("it adds names if needed", {
-  t1 <- list(); t1[[a]] <- 1:10
-  t2 <- list(); t2[[b]] <- 5:15
-  res <- list(); res[[a]] <- 1:10; res[[b]] <- 5:15
+  t1 <- list()
+  t2 <- list()
+  res <- list()
+  t1[[a]] <- 1:10
+  t2[[b]] <- 5:15
+  res[[a]] <- 1:10
+  res[[b]] <- 5:15
   expect_equal(normalize_exclusions(c(t1, t2)), res)
 })
 
 test_that("it handles full file exclusions", {
-  res <- list(); res[[a]] <- Inf
+  res <- list()
+  res[[a]] <- Inf
   expect_equal(normalize_exclusions(list(a)), res)
 
-  t1 <- list(); t1[[1]] <- a; t1[[b]] <- 1
-  res <- list(); res[[a]] <- Inf; res[[b]] <- 1
+  t1 <- list()
+  res <- list()
+  t1[[1]] <- a
+  t1[[b]] <- 1
+  res[[a]] <- Inf
+  res[[b]] <- 1
   expect_equal(normalize_exclusions(t1), res)
 })
 
 test_that("it handles redundant lines", {
-  t1 <- list(); t1[[a]] <- c(1, 1, 1:10)
-  res <- list(); res[[a]] <- 1:10
+  t1 <- list()
+  res <- list()
+  t1[[a]] <- c(1, 1, 1:10)
+  res[[a]] <- 1:10
   expect_equal(normalize_exclusions(t1), res)
 
-  t1 <- list(); t1[[a]] <-  c(1, 1, 1:10); t1[[b]] <- 1:10
-  res <- list(); res[[a]] <- 1:10; res[[b]] <- 1:10
+  t1 <- list()
+  res <- list()
+  t1[[a]] <- c(1, 1, 1:10)
+  t1[[b]] <- 1:10
+  res[[a]] <- 1:10
+  res[[b]] <- 1:10
   expect_equal(normalize_exclusions(t1), res)
 })
 
 test_that("it handles redundant files", {
-  t1 <- list(1:10, 10:20); names(t1) <- c(a, a)
-  res <- list(); res[[a]] <- 1:20
+  t1 <- list(1:10, 10:20)
+  names(t1) <- c(a, a)
+  res <- list()
+  res[[a]] <- 1:20
   expect_equal(normalize_exclusions(t1), res)
 })
 
 test_that("it normalizes file paths, removing non-existing files", {
-  t1 <- list(); t1[[a]] <- 1:10
-  t2 <- list(); t2[["notafile"]] <- 5:15
-  t3 <- list(); t3[[c]] <- 5:15
-  res <- list(); res[[a]] <- 1:10; res[[normalizePath(c)]] <- 5:15
+  t1 <- list()
+  t2 <- list()
+  t3 <- list()
+  res <- list()
+  t1[[a]] <- 1:10
+  t2[["notafile"]] <- 5:15
+  t3[[c]] <- 5:15
+  res[[a]] <- 1:10
+  res[[normalizePath(c)]] <- 5:15
   expect_equal(normalize_exclusions(c(t1, t2, t3)), res)
 
-  res <- list(); res[[a]] <- 1:10; res[["notafile"]] <- 5:15; res[[c]] <- 5:15
+  res <- list()
+  res[[a]] <- 1:10
+  res[["notafile"]] <- 5:15
+  res[[c]] <- 5:15
   expect_equal(normalize_exclusions(c(t1, t2, t3), normalize_path = FALSE), res)
 })