3 files changed, 6 insertions, 6 deletions
diff --git a/src/inbound_group_session.c b/src/inbound_group_session.c
index a78404d..7e96294 100644
--- a/src/inbound_group_session.c
+++ b/src/inbound_group_session.c
@@ -58,7 +58,7 @@ struct OlmInboundGroupSession {
     enum OlmErrorCode last_error;
 };
 
-size_t olm_inbound_group_session_size() {
+size_t olm_inbound_group_session_size(void) {
     return sizeof(OlmInboundGroupSession);
 }
 
diff --git a/src/olm.cpp b/src/olm.cpp
index d3af19c..d626c84 100644
--- a/src/olm.cpp
+++ b/src/olm.cpp
@@ -104,7 +104,7 @@ void olm_get_library_version(uint8_t *major, uint8_t *minor, uint8_t *patch) {
     if (patch != NULL) *patch = OLMLIB_VERSION_PATCH;
 }
 
-size_t olm_error() {
+size_t olm_error(void) {
     return std::size_t(-1);
 }
 
@@ -131,16 +131,16 @@ const char * olm_utility_last_error(
     return _olm_error_to_string(error);
 }
 
-size_t olm_account_size() {
+size_t olm_account_size(void) {
     return sizeof(olm::Account);
 }
 
 
-size_t olm_session_size() {
+size_t olm_session_size(void) {
     return sizeof(olm::Session);
 }
 
-size_t olm_utility_size() {
+size_t olm_utility_size(void) {
     return sizeof(olm::Utility);
 }
 
diff --git a/src/outbound_group_session.c b/src/outbound_group_session.c
index 2019844..74ce68d 100644
--- a/src/outbound_group_session.c
+++ b/src/outbound_group_session.c
@@ -43,7 +43,7 @@ struct OlmOutboundGroupSession {
 };
 
 
-size_t olm_outbound_group_session_size() {
+size_t olm_outbound_group_session_size(void) {
     return sizeof(OlmOutboundGroupSession);
 }