diff --git a/src/runtime/c/gu/mem.h b/src/runtime/c/gu/mem.h
index f26e4d3a4..1d4a52bf9 100644
--- a/src/runtime/c/gu/mem.h
+++ b/src/runtime/c/gu/mem.h
@@ -57,7 +57,7 @@ gu_local_pool_(uint8_t* init_buf, size_t sz);
 
 /// Create a pool where each chunk is corresponds to one or
 /// more pages.
-GU_API GuPool*
+GU_API_DECL GuPool*
 gu_new_page_pool(void);
 
 /// Create a pool stored in a memory mapped file.
@@ -204,7 +204,7 @@ gu_mem_buf_realloc(
 	size_t* real_size_out);
 
 /// Allocate enough memory pages to contain min_size bytes.
-GU_API void*
+GU_API_DECL void*
 gu_mem_page_alloc(size_t min_size, size_t* real_size_out);
 
 /// Free a memory buffer.
diff --git a/src/runtime/c/gu/seq.h b/src/runtime/c/gu/seq.h
index 3b345be61..b639369c3 100644
--- a/src/runtime/c/gu/seq.h
+++ b/src/runtime/c/gu/seq.h
@@ -183,7 +183,7 @@ gu_buf_heapify(GuBuf *buf, GuOrder *order);
 GU_API_DECL GuSeq*
 gu_buf_freeze(GuBuf* buf, GuPool* pool);
 
-GU_API void
+GU_API_DECL void
 gu_buf_evacuate(GuBuf* buf, GuPool* pool);
 #endif // GU_SEQ_H_
 
diff --git a/src/runtime/c/pgf/expr.h b/src/runtime/c/pgf/expr.h
index e560d3a83..b775bd9b5 100644
--- a/src/runtime/c/pgf/expr.h
+++ b/src/runtime/c/pgf/expr.h
@@ -197,16 +197,16 @@ pgf_literal_hash(GuHash h, PgfLiteral lit);
 PGF_API_DECL GuHash
 pgf_expr_hash(GuHash h, PgfExpr e);
 
-PGF_API size_t
+PGF_API_DECL size_t
 pgf_expr_size(PgfExpr expr);
 
-PGF_API GuSeq*
+PGF_API_DECL GuSeq*
 pgf_expr_functions(PgfExpr expr, GuPool* pool);
 
-PGF_API PgfExpr
+PGF_API_DECL PgfExpr
 pgf_expr_substitute(PgfExpr expr, GuSeq* meta_values, GuPool* pool);
 
-PGF_API PgfType*
+PGF_API_DECL PgfType*
 pgf_type_substitute(PgfType* type, GuSeq* meta_values, GuPool* pool);
 
 typedef struct PgfPrintContext PgfPrintContext;