diff --git a/src/pulse/stream.c b/src/pulse/stream.c
index d1ccfbca9..bb2115ac3 100644
--- a/src/pulse/stream.c
+++ b/src/pulse/stream.c
@@ -345,7 +345,7 @@ pa_context* pa_stream_get_context(const pa_stream *s) {
     return s->context;
 }
 
-uint32_t pa_stream_get_index(pa_stream *s) {
+uint32_t pa_stream_get_index(const pa_stream *s) {
     pa_assert(s);
     pa_assert(PA_REFCNT_VALUE(s) >= 1);
 
diff --git a/src/pulse/stream.h b/src/pulse/stream.h
index 4c52c3107..63289141b 100644
--- a/src/pulse/stream.h
+++ b/src/pulse/stream.h
@@ -352,7 +352,7 @@ pa_context* pa_stream_get_context(const pa_stream *p);
  * introspection functions such as pa_context_get_sink_input_info()
  * or pa_context_get_source_output_info(). This returns PA_INVALID_INDEX
  * on failure. */
-uint32_t pa_stream_get_index(pa_stream *s);
+uint32_t pa_stream_get_index(const pa_stream *s);
 
 /** Return the index of the sink or source this stream is connected to
  * in the server. This is useful with the introspection