diff --git a/src/pulse/context.c b/src/pulse/context.c
index 96193bdf5..3f7e6534f 100644
--- a/src/pulse/context.c
+++ b/src/pulse/context.c
@@ -1338,7 +1338,7 @@ uint32_t pa_context_get_protocol_version(const pa_context *c) {
     return PA_PROTOCOL_VERSION;
 }
 
-uint32_t pa_context_get_server_protocol_version(pa_context *c) {
+uint32_t pa_context_get_server_protocol_version(const pa_context *c) {
     pa_assert(c);
     pa_assert(PA_REFCNT_VALUE(c) >= 1);
 
diff --git a/src/pulse/context.h b/src/pulse/context.h
index 1197a2ecd..7298a0879 100644
--- a/src/pulse/context.h
+++ b/src/pulse/context.h
@@ -240,7 +240,7 @@ uint32_t pa_context_get_protocol_version(const pa_context *c);
 
 /** Return the protocol version of the connected server.
  * Returns PA_INVALID_INDEX on error. */
-uint32_t pa_context_get_server_protocol_version(pa_context *c);
+uint32_t pa_context_get_server_protocol_version(const pa_context *c);
 
 /** Update the property list of the client, adding new entries. Please
  * note that it is highly recommended to set as many properties