diff --git a/src/lib/barrier/ClientApp.cpp b/src/lib/barrier/ClientApp.cpp
index ca9ac4ce..87686f29 100644
--- a/src/lib/barrier/ClientApp.cpp
+++ b/src/lib/barrier/ClientApp.cpp
@@ -116,8 +116,8 @@ ClientApp::help()
     "      --display <display>  connect to the X server at <display>\n" \
     "      --no-xinitthreads    do not call XInitThreads()\n"
 #else
-#  define WINAPI_ARG
-#  define WINAPI_INFO
+#  define WINAPI_ARG ""
+#  define WINAPI_INFO ""
 #endif
 
     std::ostringstream buffer;
diff --git a/src/lib/barrier/ServerApp.cpp b/src/lib/barrier/ServerApp.cpp
index b9df07cb..112f2902 100644
--- a/src/lib/barrier/ServerApp.cpp
+++ b/src/lib/barrier/ServerApp.cpp
@@ -117,8 +117,8 @@ ServerApp::help()
     "      --display <display>  connect to the X server at <display>\n" \
     "      --no-xinitthreads    do not call XInitThreads()\n"
 #else
-#  define WINAPI_ARGS
-#  define WINAPI_INFO
+#  define WINAPI_ARGS ""
+#  define WINAPI_INFO ""
 #endif
 
     std::ostringstream buffer;