diff --git a/miniz_tdef.c b/miniz_tdef.c
index b3e95f2..313a03c 100644
--- a/miniz_tdef.c
+++ b/miniz_tdef.c
@@ -1559,7 +1559,7 @@ void *tdefl_write_image_to_png_file_in_memory(const void *pImage, int w, int h,
 /* Allocate the tdefl_compressor and tinfl_decompressor structures in C so that */
 /* non-C language bindings to tdefL_ and tinfl_ API don't need to worry about */
 /* structure size and allocation mechanism. */
-tdefl_compressor *tdefl_compressor_alloc()
+tdefl_compressor *tdefl_compressor_alloc(void)
 {
     return (tdefl_compressor *)MZ_MALLOC(sizeof(tdefl_compressor));
 }
diff --git a/miniz_tinfl.c b/miniz_tinfl.c
index a62cdaa..938ca09 100644
--- a/miniz_tinfl.c
+++ b/miniz_tinfl.c
@@ -724,7 +724,7 @@ int tinfl_decompress_mem_to_callback(const void *pIn_buf, size_t *pIn_buf_size,
 }
 
 #ifndef MINIZ_NO_MALLOC
-tinfl_decompressor *tinfl_decompressor_alloc()
+tinfl_decompressor *tinfl_decompressor_alloc(void)
 {
     tinfl_decompressor *pDecomp = (tinfl_decompressor *)MZ_MALLOC(sizeof(tinfl_decompressor));
     if (pDecomp)