diff --git a/src/bloom.h b/src/bloom.h
index 74f64ca..b03ad32 100755
--- a/src/bloom.h
+++ b/src/bloom.h
@@ -204,7 +204,7 @@ void bloom_free(struct bloom * bloom);
  * Return: version string
  *
  */
-const char * bloom_version();
+const char * bloom_version(void);
 
 
 #endif
diff --git a/src/libecoPCR/ecoPCR.h b/src/libecoPCR/ecoPCR.h
index d4cd399..98f5937 100644
--- a/src/libecoPCR/ecoPCR.h
+++ b/src/libecoPCR/ecoPCR.h
@@ -57,7 +57,7 @@ typedef struct {
  * 
  */
 
-int32_t is_big_endian();
+int32_t is_big_endian(void);
 int32_t swap_int32_t(int32_t);
 
 void   *eco_malloc(int32_t chunksize,
@@ -77,8 +77,8 @@ void    eco_free(void *chunk,
                  const char *filename,
                  int32_t    line);
                  
-void    eco_trace_memory_allocation();
-void    eco_untrace_memory_allocation();
+void    eco_trace_memory_allocation(void);
+void    eco_untrace_memory_allocation(void);
 
 #define ECOMALLOC(size,error_message) \
 	    eco_malloc((size),(error_message),__FILE__,__LINE__)
diff --git a/src/linked_list.c b/src/linked_list.c
index 9e81251..a6e52b1 100644
--- a/src/linked_list.c
+++ b/src/linked_list.c
@@ -28,7 +28,7 @@
  * @since February 2017
  * @author Celine Mercier (celine.mercier@metabarcoding.org)
  */
-static Linked_list_node_p create_node();
+static Linked_list_node_p create_node(void);
 
 
 static Linked_list_node_p create_node()
diff --git a/src/obiavl.c b/src/obiavl.c
index 3fff360..360049d 100644
--- a/src/obiavl.c
+++ b/src/obiavl.c
@@ -99,7 +99,7 @@ static char* build_avl_data_file_name(const char* avl_name);
  * @since December 2015
  * @author Celine Mercier (celine.mercier@metabarcoding.org)
  */
-size_t get_avl_header_size();
+size_t get_avl_header_size(void);
 
 
 /**
@@ -110,7 +110,7 @@ size_t get_avl_header_size();
  * @since December 2015
  * @author Celine Mercier (celine.mercier@metabarcoding.org)
  */
-size_t get_initial_avl_size();
+size_t get_initial_avl_size(void);
 
 
 /**
@@ -122,7 +122,7 @@ size_t get_initial_avl_size();
  * @since December 2015
  * @author Celine Mercier (celine.mercier@metabarcoding.org)
  */
-size_t get_avl_data_header_size();
+size_t get_avl_data_header_size(void);
 
 
 /**
@@ -134,7 +134,7 @@ size_t get_avl_data_header_size();
  * @since December 2015
  * @author Celine Mercier (celine.mercier@metabarcoding.org)
  */
-size_t get_initial_avl_data_size();
+size_t get_initial_avl_data_size(void);
 
 
 /**
diff --git a/src/obidms.c b/src/obidms.c
index 6d426e6..6994cd8 100644
--- a/src/obidms.c
+++ b/src/obidms.c
@@ -94,7 +94,7 @@ static char* build_infos_file_name(const char* dms_name);
  * @since September 2018
  * @author Celine Mercier (celine.mercier@metabarcoding.org)
  */
-static size_t get_platform_infos_file_size();
+static size_t get_platform_infos_file_size(void);
 
 
 /**
diff --git a/src/obidms.h b/src/obidms.h
index cc92196..daa0e17 100644
--- a/src/obidms.h
+++ b/src/obidms.h
@@ -477,7 +477,7 @@ int obi_import_view(const char* dms_path_1, const char* dms_path_2, const char*
  * @since October 2017
  * @author Celine Mercier (celine.mercier@metabarcoding.org)
  */
-void obi_close_atexit();
+void obi_close_atexit(void);
 
 
 #endif /* OBIDMS_H_ */
diff --git a/src/obilittlebigman.h b/src/obilittlebigman.h
index da97d22..156d098 100644
--- a/src/obilittlebigman.h
+++ b/src/obilittlebigman.h
@@ -55,7 +55,7 @@
  * @since May 2015
  * @author Eric Coissac (eric.coissac@metabarcoding.org)
  */
-bool obi_is_little_endian();
+bool obi_is_little_endian(void);
 
 
 #endif /* OBILITTLEBIGMAN_H_ */
diff --git a/src/obiview.c b/src/obiview.c
index a73e4f8..7ba74bf 100644
--- a/src/obiview.c
+++ b/src/obiview.c
@@ -105,7 +105,7 @@ static bool view_exists(OBIDMS_p dms, const char* view_name);
  * @since June 2016
  * @author Celine Mercier (celine.mercier@metabarcoding.org)
  */
-static size_t get_platform_view_file_size();
+static size_t get_platform_view_file_size(void);
 
 
 /**