diff --git a/src/lib-sieve/sieve-message.c b/src/lib-sieve/sieve-message.c
index 672cf079c174efbe6fc53e97f9c315bd96cc6851..f6e94383a7dde3a1f08b6be07c0b105a8b05b30c 100644
--- a/src/lib-sieve/sieve-message.c
+++ b/src/lib-sieve/sieve-message.c
@@ -273,9 +273,8 @@ void sieve_message_context_extension_set(struct sieve_message_context *msgctx,
 	array_idx_set(&msgctx->ext_contexts, (unsigned int)ext->id, &context);
 }
 
-const void *
-sieve_message_context_extension_get(struct sieve_message_context *msgctx,
-				    const struct sieve_extension *ext)
+void *sieve_message_context_extension_get(struct sieve_message_context *msgctx,
+					  const struct sieve_extension *ext)
 {
 	void *const *ctx;
 
diff --git a/src/lib-sieve/sieve-message.h b/src/lib-sieve/sieve-message.h
index 09d6b70fde981ba4d256158e814f1090a60fc356..5f608e9797dc63e74570e23515ca0ecb44f08e7b 100644
--- a/src/lib-sieve/sieve-message.h
+++ b/src/lib-sieve/sieve-message.h
@@ -36,9 +36,8 @@ void sieve_message_context_time(struct sieve_message_context *msgctx,
 void sieve_message_context_extension_set(struct sieve_message_context *msgctx,
 					 const struct sieve_extension *ext,
 					 void *context);
-const void *sieve_message_context_extension_get(
-	struct sieve_message_context *msgctx,
-	const struct sieve_extension *ext);
+void *sieve_message_context_extension_get(struct sieve_message_context *msgctx,
+					  const struct sieve_extension *ext);
 
 /* Envelope */