diff --git a/src/generate/generate.nim b/src/generate/generate.nim
index 01579587..32814025 100644
--- a/src/generate/generate.nim
+++ b/src/generate/generate.nim
@@ -157,10 +157,17 @@ proc generateImpl(trackDir: Path, conf: Conf): seq[PathAndGeneratedDocument] =
                                          slugLookup)
     let introductionPath = introductionTemplatePath.string[0..^5] # Removes `.tpl`
 
-    if fileExists(introductionPath) and readFile(introductionPath) == generated:
-      logDetailed(&"Up-to-date: {relativePath(introductionPath, $trackDir)}")
+    if fileExists(introductionPath):
+      if readFile(introductionPath) == generated:
+        logDetailed(&"Up-to-date: {relativePath(introductionPath, $trackDir)}")
+      else:
+        logNormal(&"Outdated: {relativePath(introductionPath, $trackDir)}")
+        result.add PathAndGeneratedDocument(
+          path: introductionPath,
+          generatedDocument: generated
+        )
     else:
-      logNormal(&"Outdated: {relativePath(introductionPath, $trackDir)}")
+      logNormal(&"Missing: {relativePath(introductionPath, $trackDir)}")
       result.add PathAndGeneratedDocument(
         path: introductionPath,
         generatedDocument: generated
diff --git a/tests/test_binary_generate.nim b/tests/test_binary_generate.nim
index bcb6c4b8..48ac54f3 100644
--- a/tests/test_binary_generate.nim
+++ b/tests/test_binary_generate.nim
@@ -55,7 +55,7 @@ proc main =
 
     test "`configlet generate` exits with 0 for a valid `.md.tpl` file":
       const expectedOutput = fmt"""
-        Outdated: {"exercises"/"concept"/"bird-count"/".docs"/"introduction.md"}
+        Missing: {"exercises"/"concept"/"bird-count"/".docs"/"introduction.md"}
         Generated 1 file
       """.unindent().replace("\p", "\n")
       execAndCheck(0, generateCmdUpdateYes, expectedOutput)
@@ -67,9 +67,9 @@ proc main =
     prepareIntroductionFiles(trackDir, "%{ concept : recursion }",
                              removeIntro = true)
 
-    test "`configlet generate` exits with 0 for valid placeholder usage with spaces":
+    test "`configlet generate` exits with 0 for valid placeholder usage with spaces, intro does not exist":
       const expectedOutput = fmt"""
-        Outdated: {"exercises"/"concept"/"bird-count"/".docs"/"introduction.md"}
+        Missing: {"exercises"/"concept"/"bird-count"/".docs"/"introduction.md"}
         Generated 1 file
       """.unindent().replace("\p", "\n")
       execAndCheck(0, generateCmdUpdateYes, expectedOutput)
@@ -77,5 +77,43 @@ proc main =
     test "and writes the `introduction.md` file as expected":
       checkNoDiff(trackDir)
 
+    # Valid placeholder syntax with spaces, and valid slug
+    prepareIntroductionFiles(trackDir, "%{ concept : atoms }",
+                             removeIntro = false)
+
+    test "`configlet generate` exits with 0 for valid placeholder usage with spaces, intro exists":
+      const expectedOutput = fmt"""
+        Outdated: {"exercises"/"concept"/"bird-count"/".docs"/"introduction.md"}
+        Generated 1 file
+      """.unindent().replace("\p", "\n")
+      execAndCheck(0, generateCmdUpdateYes, expectedOutput)
+
+    test "and writes the `introduction.md` file as expected":
+      const expectedDiff = """
+        --- exercises/concept/bird-count/.docs/introduction.md
+        +++ exercises/concept/bird-count/.docs/introduction.md
+        -## Recursion
+        +## Atoms
+        -Recursive functions are functions that call themselves.
+        -
+        -A recursive function needs to have at least one _base case_ and at least one _recursive case_.
+        -
+        -A _base case_ returns a value without calling the function again. A _recursive case_ calls the function again, modifying the input so that it will at some point match the base case.
+        -
+        -Very often, each case is written in its own function clause.
+        +Elixir's `atom` type represents a fixed constant. An atom's value is simply its own name. This gives us a type-safe way to interact with data. Atoms can be defined as follows:
+        -# base case
+        -def count([]), do: 0
+        -
+        -# recursive case
+        -def count([_head | tail]), do: 1 + count(tail)
+        +# All atoms are preceded with a ':' then follow with alphanumeric snake-cased characters
+        +variable = :an_atom
+        +
+        +_Atoms_ are internally represented by an integer in a lookup table, which are set automatically. It is not possible to change this internal value.
+      """.unindent().replace("\p", "\n")
+      testDiffThenRestore(trackDir, expectedDiff, "exercises"/"concept"/"bird-count"/".docs"/"introduction.md")
+      removeFile(trackDir / "exercises"/"concept"/"bird-count"/".docs"/"introduction.md.tpl")
+
 main()
 {.used.}