diff --git a/c/include/brunsli/decode.h b/c/include/brunsli/decode.h
index cedaa2f..01fce8d 100644
--- a/c/include/brunsli/decode.h
+++ b/c/include/brunsli/decode.h
@@ -27,6 +27,9 @@ Outputs to out_fun, out_fun must return amount of consumed bytes, any return
 value not equal to the input size is considered an error. It will pass on the
 out_data to out_fun.
 */
+#if defined(_MSC_VER) && defined(brunslidec_c_EXPORTS)
+__declspec(dllexport)
+#endif
 int DecodeBrunsli(size_t in_size, const uint8_t* in, void* out_data,
                   DecodeBrunsliSink out_fun);
 
diff --git a/c/include/brunsli/encode.h b/c/include/brunsli/encode.h
index f1bcf45..f543f7e 100644
--- a/c/include/brunsli/encode.h
+++ b/c/include/brunsli/encode.h
@@ -24,6 +24,9 @@ Outputs to outfun, outfun must return amount of consumed bytes, any return value
 not equal to the input size is considered an error. It will pass on the outdata
 to outfun.
 */
+#if defined(_MSC_VER) && defined(brunslienc_c_EXPORTS)
+__declspec(dllexport)
+#endif
 int EncodeBrunsli(size_t insize, const unsigned char* in, void* outdata,
     size_t (*outfun)(void* outdata, const unsigned char* buf, size_t size));