diff --git a/CHANGELOG.md b/CHANGELOG.md
index ec13bd9..14aeb32 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   the command line tools.
 
 ### Fixed
+- Sample-based oscillators could hard crash if a x87 stack overflow happened
+  when calculating the current position in the sample ([#149][i149])
 - Numeric updown widget calculated dp-to-px conversion incorrectly, resulting in
   wrong scaling ([#150][i150])
 - Empty patch should not crash the native synth ([#148][i148])
@@ -215,4 +217,5 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 [i145]: https://github.com/vsariola/sointu/issues/145
 [i146]: https://github.com/vsariola/sointu/issues/146
 [i148]: https://github.com/vsariola/sointu/issues/148
+[i149]: https://github.com/vsariola/sointu/issues/149
 [i150]: https://github.com/vsariola/sointu/issues/150
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 268e160..15904d0 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -181,3 +181,8 @@ target_compile_definitions(test_render_samples PUBLIC TEST_HEADER="test_render_s
 add_executable(test_render_samples_api test_render_samples_api.c)
 target_link_libraries(test_render_samples_api ${STATICLIB})
 add_test(test_render_samples_api test_render_samples_api)
+
+add_executable(test_oscillator_crash test_oscillator_crash.c)
+target_link_libraries(test_oscillator_crash ${STATICLIB})
+add_test(test_oscillator_crash test_oscillator_crash)
+
diff --git a/tests/test_oscillator_crash.c b/tests/test_oscillator_crash.c
new file mode 100644
index 0000000..ebe319b
--- /dev/null
+++ b/tests/test_oscillator_crash.c
@@ -0,0 +1,55 @@
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <sointu.h>
+
+#define BPM 100
+#define SAMPLE_RATE 44100
+#define LENGTH_IN_ROWS 16
+#define SAMPLES_PER_ROW SAMPLE_RATE * 4 * 60 / (BPM * 16)
+const int su_max_samples = SAMPLES_PER_ROW * LENGTH_IN_ROWS;
+
+int main(int argc, char* argv[])
+{
+    Synth* synth;
+    float* buffer;
+    // The patch is invalid and overflows the stack. This should still exit cleanly, but used to hard crash.
+    // See: https://github.com/vsariola/sointu/issues/149
+    const unsigned char opcodes[] = { SU_OSCILLATOR_ID + 1, // STEREO                                     
+                                     SU_ADVANCE_ID };
+    const unsigned char operands[] = { 69, 74, 0, 0, 82, 128, 128 };
+    int errcode;
+    int time;
+    int samples;
+    int totalrendered;
+    int retval;
+    // initialize Synth
+    synth = (Synth*)malloc(sizeof(Synth));
+    memset(synth, 0, sizeof(Synth));
+    memcpy(synth->Opcodes, opcodes, sizeof(opcodes));
+    memcpy(synth->Operands, operands, sizeof(operands));
+    synth->NumVoices = 3;
+    synth->Polyphony = 6;
+    synth->RandSeed = 1;
+    synth->SampleOffsets[0].Start = 91507;
+    synth->SampleOffsets[0].LoopStart = 5448;
+    synth->SampleOffsets[0].LoopLength = 563;
+    // initialize Buffer
+    buffer = (float*)malloc(2 * sizeof(float) * su_max_samples);
+    // triger first voice
+    synth->SynthWrk.Voices[0].Note = 64;
+    synth->SynthWrk.Voices[0].Sustain = 1;
+    totalrendered = 0;
+    samples = su_max_samples;
+    time = INT32_MAX;
+    retval = 0;    
+    errcode = su_render(synth, buffer, &samples, &time);
+    if (errcode != 0x1041) {
+        retval = 1;
+        printf("su_render should have return errcode 0x1401, got 0x%08x\n", errcode);
+    }       
+    free(synth);
+    free(buffer);
+    return retval;
+}
diff --git a/vm/compiler/templates/amd64-386/sources.asm b/vm/compiler/templates/amd64-386/sources.asm
index 872f82a..9611c03 100644
--- a/vm/compiler/templates/amd64-386/sources.asm
+++ b/vm/compiler/templates/amd64-386/sources.asm
@@ -338,7 +338,7 @@ su_oscillat_gate_bit:                           ; stack: 0/1, let's call it x
     pop     {{.DX}}                                             ; edx is now the sample number
     movzx   ebx, word [{{.DI}} + 4]    ; ecx = loopstart
     sub     edx, ebx                                        ; if sample number < loop start
-    jl      su_oscillat_sample_not_looping                  ;   then we're not looping yet
+    jb      su_oscillat_sample_not_looping                  ;   then we're not looping yet
     mov     eax, edx                                        ; eax = sample number
     movzx   ecx, word [{{.DI}} + 6]   ; edi is now the loop length
     xor     edx, edx                                        ; div wants edx to be empty