diff --git a/aegisub/build/aegisub_vs2008/aegisub_vs2008.vcproj b/aegisub/build/aegisub_vs2008/aegisub_vs2008.vcproj
index daf68b8e2..0c5a6f4e3 100644
--- a/aegisub/build/aegisub_vs2008/aegisub_vs2008.vcproj
+++ b/aegisub/build/aegisub_vs2008/aegisub_vs2008.vcproj
@@ -493,6 +493,14 @@
 				RelativePath="..\..\src\audio_provider_hd.h"
 				>
 			</File>
+			<File
+				RelativePath="..\..\src\audio_provider_lock.cpp"
+				>
+			</File>
+			<File
+				RelativePath="..\..\src\audio_provider_lock.h"
+				>
+			</File>
 			<File
 				RelativePath="..\..\src\audio_provider_pcm.cpp"
 				>
diff --git a/aegisub/src/Makefile b/aegisub/src/Makefile
index 47d2fde7b..4b4bf9dee 100644
--- a/aegisub/src/Makefile
+++ b/aegisub/src/Makefile
@@ -145,6 +145,7 @@ SRC += \
 	audio_provider.cpp \
 	audio_provider_convert.cpp \
 	audio_provider_hd.cpp \
+	audio_provider_lock.cpp \
 	audio_provider_pcm.cpp \
 	audio_provider_ram.cpp \
 	audio_renderer.cpp \
diff --git a/aegisub/src/audio_provider.cpp b/aegisub/src/audio_provider.cpp
index e1c45cc4d..7175fe439 100644
--- a/aegisub/src/audio_provider.cpp
+++ b/aegisub/src/audio_provider.cpp
@@ -50,6 +50,7 @@
 #include "audio_provider_ffmpegsource.h"
 #endif
 #include "audio_provider_hd.h"
+#include "audio_provider_lock.h"
 #include "audio_provider_pcm.h"
 #include "audio_provider_ram.h"
 #include "compat.h"
@@ -152,7 +153,7 @@ AudioProvider *AudioProviderFactory::GetProvider(wxString const& filename, int c
 	// Change provider to RAM/HD cache if needed
 	if (cache == -1) cache = OPT_GET("Audio/Cache/Type")->GetInt();
 	if (!cache || !needsCache) {
-		return provider;
+		return new LockAudioProvider(provider);
 	}
 
 	DialogProgress progress(wxGetApp().frame, _("Load audio"));
diff --git a/aegisub/src/audio_provider_lock.cpp b/aegisub/src/audio_provider_lock.cpp
new file mode 100644
index 000000000..35e5e259d
--- /dev/null
+++ b/aegisub/src/audio_provider_lock.cpp
@@ -0,0 +1,36 @@
+// Copyright (c) 2012, Thomas Goyne <plorkyeran@aegisub.org>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+// $Id$
+
+/// @file audio_provider_lock.cpp
+/// @brief An audio provider adapter for un-threadsafe audio providers
+/// @ingroup audio_input
+
+#include "config.h"
+
+#include "audio_provider_lock.h"
+
+LockAudioProvider::LockAudioProvider(AudioProvider *source) : source(source) {
+	channels = source->GetChannels();
+	num_samples = source->GetNumSamples();
+	sample_rate = source->GetSampleRate();
+	bytes_per_sample = source->GetBytesPerSample();
+	float_samples = source->AreSamplesFloat();
+}
+
+void LockAudioProvider::GetAudio(void *buf, int64_t start, int64_t count) const {
+	wxMutexLocker lock(mutex);
+	source->GetAudio(buf, start, count);
+}
diff --git a/aegisub/src/audio_provider_lock.h b/aegisub/src/audio_provider_lock.h
new file mode 100644
index 000000000..e00db08d0
--- /dev/null
+++ b/aegisub/src/audio_provider_lock.h
@@ -0,0 +1,37 @@
+// Copyright (c) 2012, Thomas Goyne <plorkyeran@aegisub.org>
+//
+// Permission to use, copy, modify, and distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+// ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+// ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+// OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+//
+// $Id$
+
+/// @file audio_provider_lock.h
+/// @brief An audio provider adapter for un-threadsafe audio providers
+/// @ingroup audio_input
+
+#include "include/aegisub/audio_provider.h"
+
+#include <libaegisub/scoped_ptr.h>
+
+#ifndef AGI_PRE
+#include <wx/mutex.h>
+#endif
+
+class LockAudioProvider : public AudioProvider {
+	agi::scoped_ptr<const AudioProvider> source;
+	mutable wxMutex mutex;
+
+public:
+	LockAudioProvider(AudioProvider *source);
+	void GetAudio(void *buf, int64_t start, int64_t count) const;
+	bool AreSamplesNativeEndian() const { return source->AreSamplesNativeEndian(); }
+};