diff --git a/CHANGELOG.md b/CHANGELOG.md
index a3bf7d623..ba2f8f322 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 This project uses the changelog in accordance with [keepchangelog](http://keepachangelog.com/). Please use this to write notable changes, which is not the same as git commit log...
 
 ## [unreleased][unreleased]
+ - Fixed the lf sampling when bits_per_sample is less than 8 (@wh201906)
  - Added `lf em 4x70 brute` command (@adite)
 
 
diff --git a/armsrc/lfsampling.c b/armsrc/lfsampling.c
index a1ff37356..e716fa248 100644
--- a/armsrc/lfsampling.c
+++ b/armsrc/lfsampling.c
@@ -296,7 +296,9 @@ void LFSetupFPGAForADC(int divisor, bool reader_field) {
 uint32_t DoAcquisition(uint8_t decimation, uint8_t bits_per_sample, bool avg, int16_t trigger_threshold,
                        bool verbose, uint32_t sample_size, uint32_t cancel_after, int32_t samples_to_skip, bool ledcontrol) {
 
-    initSampleBuffer(&sample_size);
+    initSampleBuffer(&sample_size); // sample size in bytes
+    sample_size <<= 3; // sample size in bits
+    sample_size /= bits_per_sample; // sample count
 
     if (g_dbglevel >= DBG_DEBUG) {
         printSamples();
@@ -368,8 +370,12 @@ uint32_t DoAcquisition(uint8_t decimation, uint8_t bits_per_sample, bool avg, in
     }
 
     // Ensure that DC offset removal and noise check is performed for any device-side processing
-    removeSignalOffset(data.buffer, samples.total_saved);
-    computeSignalProperties(data.buffer, samples.total_saved);
+    if (bits_per_sample == 8)
+    {
+        // these functions only consider bps==8
+        removeSignalOffset(data.buffer, samples.total_saved);
+        computeSignalProperties(data.buffer, samples.total_saved);
+    }
     return data.numbits;
 }
 /**
diff --git a/client/src/cmddata.c b/client/src/cmddata.c
index f9a0036d8..b9ca854f1 100644
--- a/client/src/cmddata.c
+++ b/client/src/cmddata.c
@@ -1779,7 +1779,7 @@ int getSamplesEx(uint32_t start, uint32_t end, bool verbose, bool ignore_lf_conf
 
         BitstreamOut_t bout = { got, bits_per_sample * n,  0};
         uint32_t j = 0;
-        for (j = 0; j * bits_per_sample < n * 8 && j < n; j++) {
+        for (j = 0; j * bits_per_sample < n * 8 && j * bits_per_sample < MAX_GRAPH_TRACE_LEN * 8; j++) {
             uint8_t sample = getByte(bits_per_sample, &bout);
             g_GraphBuffer[j] = ((int) sample) - 127;
         }