diff --git a/include/asterisk/dsp.h b/include/asterisk/dsp.h
index 81735d625023022369012e5a733d4e4f2d7d6f19..871a51ac9a2e37acbbfd58ff7ef9627b88e84823 100644
--- a/include/asterisk/dsp.h
+++ b/include/asterisk/dsp.h
@@ -138,4 +138,16 @@ int ast_dsp_reload(void);
 
 int ast_dsp_init(void);
 
+/*!
+ * \brief Hint that a frame from a dsp was freed
+ *
+ * This is called from ast_frame_free if AST_FRFLAG_FROM_DSP is set. This occurs
+ * because it is possible for the dsp to be freed while someone still holds a reference
+ * to the frame that is in that dsp. This has been known to happen when the dsp on a Zap
+ * channel detects a busy signal. The channel is hung up, and the application that read the
+ * frame to begin with still has a reference to the frame.
+ *
+ * \return nothing
+ */
+void ast_dsp_frame_freed(struct ast_frame *fr);
 #endif /* _ASTERISK_DSP_H */
diff --git a/include/asterisk/frame.h b/include/asterisk/frame.h
index ad4b8292006bfd3aed303f939ceba2b1b0444f2d..719048b02c371242bdcc52268256785a549b0fbc 100644
--- a/include/asterisk/frame.h
+++ b/include/asterisk/frame.h
@@ -130,6 +130,10 @@ enum {
 	 *  The translator can not be free'd if the frame inside of it still has
 	 *  this flag set. */
 	AST_FRFLAG_FROM_TRANSLATOR = (1 << 1),
+	/*! This frame came from a dsp and is still the original frame.
+	 *  The dsp cannot be free'd if the frame inside of it still has
+	 *  this flag set. */
+	AST_FRFLAG_FROM_DSP = (1 << 2),
 };
 
 /*! \brief Data structure associated with a single frame of data
diff --git a/main/dsp.c b/main/dsp.c
index f2d47df595349cc4885cf82d1cae03b53d6a829f..935bcb0bf713529efce073749d1bf24f1a10d298 100644
--- a/main/dsp.c
+++ b/main/dsp.c
@@ -388,6 +388,7 @@ struct ast_dsp {
 	digit_detect_state_t digit_state;
 	tone_detect_state_t cng_tone_state;
 	tone_detect_state_t ced_tone_state;
+	int destroy;
 };
 
 static void mute_fragment(struct ast_dsp *dsp, fragment_t *fragment)
@@ -1310,6 +1311,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 		memset(&dsp->f, 0, sizeof(dsp->f));
 		dsp->f.frametype = AST_FRAME_NULL;
 		ast_frfree(af);
+		ast_set_flag(&dsp->f, AST_FRFLAG_FROM_DSP);
 		return &dsp->f;
 	}
 	if ((dsp->features & DSP_FEATURE_BUSY_DETECT) && ast_dsp_busydetect(dsp)) {
@@ -1319,6 +1321,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 		dsp->f.subclass = AST_CONTROL_BUSY;
 		ast_frfree(af);
 		ast_debug(1, "Requesting Hangup because the busy tone was detected on channel %s\n", chan->name);
+		ast_set_flag(&dsp->f, AST_FRFLAG_FROM_DSP);
 		return &dsp->f;
 	}
 
@@ -1424,6 +1427,7 @@ done:
 		if (chan) 
 			ast_queue_frame(chan, af);
 		ast_frfree(af);
+		ast_set_flag(outf, AST_FRFLAG_FROM_DSP);
 		return outf;
 	} else {
 		return af;
@@ -1474,6 +1478,16 @@ void ast_dsp_set_features(struct ast_dsp *dsp, int features)
 
 void ast_dsp_free(struct ast_dsp *dsp)
 {
+	if (ast_test_flag(&dsp->f, AST_FRFLAG_FROM_DSP)) {
+		/* If this flag is still set, that means that the dsp's destruction 
+		 * been torn down, while we still have a frame out there being used.
+		 * When ast_frfree() gets called on that frame, this ast_trans_pvt
+		 * will get destroyed, too. */
+
+		dsp->destroy = 1;
+
+		return;
+	}
 	ast_free(dsp);
 }
 
@@ -1632,3 +1646,16 @@ int ast_dsp_reload(void)
 	return _dsp_init(1);
 }
 
+void ast_dsp_frame_freed(struct ast_frame *fr)
+{
+	struct ast_dsp *dsp;
+
+	ast_clear_flag(fr, AST_FRFLAG_FROM_DSP);
+
+	dsp = (struct ast_dsp *) (((char *) fr) - offsetof(struct ast_dsp, f));
+
+	if (!dsp->destroy)
+		return;
+	
+	ast_dsp_free(dsp);
+}
diff --git a/main/frame.c b/main/frame.c
index 3971393fd2780d26f1c79cab9e22e41e9146307f..c49e8e661933f5b5953c3195252dff22af3e9c50 100644
--- a/main/frame.c
+++ b/main/frame.c
@@ -37,6 +37,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/threadstorage.h"
 #include "asterisk/linkedlists.h"
 #include "asterisk/translate.h"
+#include "asterisk/dsp.h"
 
 #ifdef TRACE_FRAMES
 static int headers;
@@ -307,6 +308,8 @@ void ast_frame_free(struct ast_frame *fr, int cache)
 {
 	if (ast_test_flag(fr, AST_FRFLAG_FROM_TRANSLATOR))
 		ast_translate_frame_freed(fr);
+	else if (ast_test_flag(fr, AST_FRFLAG_FROM_DSP))
+		ast_dsp_frame_freed(fr);
 
 	if (!fr->mallocd)
 		return;
@@ -356,6 +359,7 @@ struct ast_frame *ast_frisolate(struct ast_frame *fr)
 	void *newdata;
 
 	ast_clear_flag(fr, AST_FRFLAG_FROM_TRANSLATOR);
+	ast_clear_flag(fr, AST_FRFLAG_FROM_DSP);
 
 	if (!(fr->mallocd & AST_MALLOCD_HDR)) {
 		/* Allocate a new header if needed */