diff --git a/src/platform_windows.cpp b/src/platform_windows.cpp
index 0ac03ef9..33858c3d 100644
--- a/src/platform_windows.cpp
+++ b/src/platform_windows.cpp
@@ -388,7 +388,7 @@ int mkstemp(char *templ)
     return _open(pathname, _O_RDWR | _O_CREAT | _O_EXCL, _S_IREAD | _S_IWRITE);
 }
 
-time_t timegm(timestamp *timeptr)
+DYNAMIC_API time_t timegm(timestamp *timeptr)
 {
     time_t result = _mkgmtime((struct tm *) timeptr);
     return result += timeptr->tm_gmtoff;
diff --git a/src/platform_windows.h b/src/platform_windows.h
index 20882837..3bc883a8 100644
--- a/src/platform_windows.h
+++ b/src/platform_windows.h
@@ -54,7 +54,7 @@ int dlclose(void *handle);
 void *dlsym(void *handle, const char *symbol);
 int mkstemp(char *templ);
 
-time_t timegm(timestamp *timeptr);
+DYNAMIC_API time_t timegm(timestamp *timeptr);
 
 #ifndef strdup
 #define strdup(A) _strdup((A))