diff --git a/lib/mojoal/mojoal.c b/lib/mojoal/mojoal.c
index ad3d72619..fb0e8a50c 100644
--- a/lib/mojoal/mojoal.c
+++ b/lib/mojoal/mojoal.c
@@ -7,10 +7,11 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>  /* needed for alloca */
 #include <math.h>
 #include <float.h>
 
-#ifdef _MSC_VER
+#ifdef _WIN32
   #define AL_API __declspec(dllexport)
   #define ALC_API __declspec(dllexport)
 #endif
@@ -532,7 +533,7 @@ struct ALCcontext_struct
 };
 
 /* forward declarations */
-static int source_get_offset(ALsource *src, ALenum param);
+static float source_get_offset(ALsource *src, ALenum param);
 static void source_set_offset(ALsource *src, ALenum param, ALfloat value);
 
 /* the just_queued list is backwards. Add it to the queue in the correct order. */
@@ -3959,31 +3960,33 @@ static void source_pause(ALCcontext *ctx, const ALuint name)
     }
 }
 
-static int source_get_offset(ALsource *src, ALenum param)
+static float source_get_offset(ALsource *src, ALenum param)
 {
     int offset = 0;
-    int framesize = sizeof(float);
+    int framesize = sizeof (float);
     int freq = 1;
     if (src->type == AL_STREAMING) {
         /* streaming: the offset counts from the first processed buffer in the queue. */
         BufferQueueItem *item = src->buffer_queue.head;
         if (item) {
-            framesize = (int)(item->buffer->channels * sizeof(float));
-            freq = (int)(item->buffer->frequency);
+            framesize = (int) (item->buffer->channels * sizeof (float));
+            freq = (int) (item->buffer->frequency);
             int proc_buf = SDL_AtomicGet(&src->buffer_queue_processed.num_items);
             offset = (proc_buf * item->buffer->len + src->offset);
         }
     } else {
-        framesize = (int)(src->buffer->channels * sizeof(float));
-        freq = (int)src->buffer->frequency;
+        framesize = (int) (src->buffer->channels * sizeof (float));
+        freq = (int) src->buffer->frequency;
         offset = src->offset;
     }
     switch(param) {
-        case AL_SAMPLE_OFFSET: return offset / framesize; break;
-        case AL_SEC_OFFSET: return (offset / framesize) / freq; break;
-        case AL_BYTE_OFFSET: return offset; break;
-        default: return 0; break;
+        case AL_SAMPLE_OFFSET: return (float) (offset / framesize); break;
+        case AL_SEC_OFFSET: return ((float) (offset / framesize)) / ((float) freq); break;
+        case AL_BYTE_OFFSET: return (float) offset; break;
+        default: break;
     }
+
+    return 0.0f;
 }
 
 static void source_set_offset(ALsource *src, ALenum param, ALfloat value)
@@ -3994,21 +3997,17 @@ static void source_set_offset(ALsource *src, ALenum param, ALfloat value)
         return;
     }
 
-    int bufflen = 0;
-    int framesize = sizeof(float);
-    int freq = 1;
-
     if (src->type == AL_STREAMING) {
         FIXME("set_offset for streaming sources not implemented");
         return;
-    } else {
-        bufflen = (int)src->buffer->len;
-        framesize = (int)(src->buffer->channels * sizeof(float));
-        freq = (int)src->buffer->frequency;
     }
 
+    const int bufflen = (int) src->buffer->len;
+    const int framesize = (int) (src->buffer->channels * sizeof (float));
+    const int freq = (int) src->buffer->frequency;
     int offset = -1;
-    switch(param) {
+
+    switch (param) {
         case AL_SAMPLE_OFFSET:
             offset = value * framesize;
             break;
@@ -4019,11 +4018,15 @@ static void source_set_offset(ALsource *src, ALenum param, ALfloat value)
             offset = ((int)value / framesize) * framesize;
             break;
     }
-    if (offset < 0 || offset > bufflen) {
+
+    if ((offset < 0) || (offset > bufflen)) {
         set_al_error(ctx, AL_INVALID_VALUE);
         return;
     }
 
+    /* make sure the offset lands on a sample frame boundary. */
+    offset -= offset % framesize;
+
     if (!SDL_AtomicGet(&src->mixer_accessible)) {
         src->offset = offset;
     } else {