diff --git a/CHANGELOG.md b/CHANGELOG.md
index 884c5e8..bf2cf40 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,7 @@ For a list of breaking changes, check [here](#breaking-changes).
 
 ## Unreleased
 
+- Fixed flushing behaviour when consuming from STDIN in the ruby-percolator example.
 - `LMGREP_FEATURE_EPSILON_GC`: use [Epsilon GC](https://www.graalvm.org/22.0/reference-manual/native-image/MemoryManagement/) in the binary.
 
 ## v2022.02.17
diff --git a/src/lmgrep/only_analyze.clj b/src/lmgrep/only_analyze.clj
index cb988bf..7fe3a0e 100644
--- a/src/lmgrep/only_analyze.clj
+++ b/src/lmgrep/only_analyze.clj
@@ -107,7 +107,8 @@
                            [nil])
         custom-analyzers (analysis/prepare-analyzers (get options :analyzers-file) options)
         ^Analyzer analyzer (analyzer/create analysis-conf custom-analyzers)
-        ^PrintWriter writer (PrintWriter. (BufferedWriter. *out* print-writer-buffer-size))]
+        ^PrintWriter writer (PrintWriter. (BufferedWriter. *out* print-writer-buffer-size)
+                                          ^Boolean (empty? files-pattern))]
     (if (get options :graph)
       (graph files-to-analyze writer analyzer options)
       (execute-analysis files-to-analyze writer analyzer options))))
diff --git a/src/lmgrep/unordered.clj b/src/lmgrep/unordered.clj
index ad39a19..6e2e1f0 100644
--- a/src/lmgrep/unordered.clj
+++ b/src/lmgrep/unordered.clj
@@ -59,7 +59,8 @@
         queue-size (get options :queue-size 1024)
         with-empty-lines (get options :with-empty-lines)
         consume-fn (if preserve-order? ordered-consume-reader unordered-consume-reader)
-        ^PrintWriter writer (PrintWriter. (BufferedWriter. *out* print-writer-buffer-size))
+        ^PrintWriter writer (PrintWriter. (BufferedWriter. *out* print-writer-buffer-size)
+                                          ^Boolean (empty? file-paths-to-analyze))
         ^ExecutorService matcher-thread-pool-executor (c/thread-pool-executor concurrency queue-size)
         ^ExecutorService writer-thread-pool-executor (c/single-thread-executor)]
     (doseq [^String path (if (empty? file-paths-to-analyze)