diff --git a/src/sfizz/Opcode.cpp b/src/sfizz/Opcode.cpp
index e860c536..f27a6685 100644
--- a/src/sfizz/Opcode.cpp
+++ b/src/sfizz/Opcode.cpp
@@ -327,6 +327,9 @@ absl::optional<bool> readBoolean(absl::string_view value)
 template <>
 absl::optional<OscillatorEnabled> Opcode::readOptional(OpcodeSpec<OscillatorEnabled>, absl::string_view value)
 {
+    if (value == "auto")
+        return OscillatorEnabled::Auto;
+
     auto v = readBoolean(value);
     if (!v)
         return absl::nullopt;
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index fcc11f51..468623b2 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -638,7 +638,7 @@ void Synth::Impl::finalizeSfzLoad()
                     region.sampleId.reset(new FileId("*silence"));
                     region.hasWavetableSample = false;
                 } else {
-                    region.hasWavetableSample |= true;
+                    region.hasWavetableSample &= true;
                 }
             }
         }
diff --git a/tests/FilesT.cpp b/tests/FilesT.cpp
index 196f5bcf..b65b9d8b 100644
--- a/tests/FilesT.cpp
+++ b/tests/FilesT.cpp
@@ -274,7 +274,7 @@ TEST_CASE("[Files] Channels (channels_multi.sfz)")
 {
     Synth synth;
     synth.loadSfzFile(fs::current_path() / "tests/TestFiles/channels_multi.sfz");
-    REQUIRE(synth.getNumRegions() == 10);
+    REQUIRE(synth.getNumRegions() == 12);
 
     int regionNumber = 0;
     const Region* region = nullptr;
@@ -327,14 +327,27 @@ TEST_CASE("[Files] Channels (channels_multi.sfz)")
     REQUIRE(!region->isOscillator());
     REQUIRE(region->oscillatorEnabled == OscillatorEnabled::Off);
 
-    // implicit wavetable (sound file < 3000 frames)
+    // implicit wavetable (sound file < 3000 frames and wavetable tags)
     region = synth.getRegionView(regionNumber++);
-    REQUIRE(region->sampleId->filename() == "ramp_wave.wav");
-    REQUIRE(!region->isStereo());
+    REQUIRE(region->sampleId->filename() == "wavetables/surge.wav");
     REQUIRE(!region->isGenerator());
     REQUIRE(region->isOscillator());
     REQUIRE(region->oscillatorEnabled == OscillatorEnabled::Auto);
 
+    // Parse oscillator=auto and same as above
+    region = synth.getRegionView(regionNumber++);
+    REQUIRE(region->sampleId->filename() == "wavetables/surge.wav");
+    REQUIRE(!region->isGenerator());
+    REQUIRE(region->isOscillator());
+    REQUIRE(region->oscillatorEnabled == OscillatorEnabled::Auto);
+
+    // implicit non wavetable (sound file < 3000 frames but no wavetable tags)
+    region = synth.getRegionView(regionNumber++);
+    REQUIRE(region->sampleId->filename() == "short_non_wavetable.wav");
+    REQUIRE(!region->isGenerator());
+    REQUIRE(!region->isOscillator());
+    REQUIRE(region->oscillatorEnabled == OscillatorEnabled::Auto);
+
     // implicit non-wavetable (sound file >= 3000 frames)
     region = synth.getRegionView(regionNumber++);
     REQUIRE(region->sampleId->filename() == "snare.wav");
diff --git a/tests/TestFiles/channels_multi.sfz b/tests/TestFiles/channels_multi.sfz
index ee6d6acf..9921b152 100644
--- a/tests/TestFiles/channels_multi.sfz
+++ b/tests/TestFiles/channels_multi.sfz
@@ -4,7 +4,9 @@
 <region> sample=ramp_wave.wav oscillator=on oscillator_multi=3
 <region> sample=ramp_wave.wav oscillator=off
 <region> sample=ramp_wave.wav oscillator=off oscillator_multi=3
-<region> sample=ramp_wave.wav
+<region> sample=wavetables/surge.wav
+<region> oscillator=auto sample=wavetables/surge.wav
+<region> sample=short_non_wavetable.wav
 <region> sample=snare.wav
 <region> sample=*sine oscillator_multi=1
 <region> sample=*sine oscillator_multi=2
diff --git a/tests/TestFiles/short_non_wavetable.wav b/tests/TestFiles/short_non_wavetable.wav
new file mode 100644
index 00000000..e71973d3
Binary files /dev/null and b/tests/TestFiles/short_non_wavetable.wav differ