diff --git a/scwx-qt/scwx-qt.cmake b/scwx-qt/scwx-qt.cmake
index 4f107883..787382a3 100644
--- a/scwx-qt/scwx-qt.cmake
+++ b/scwx-qt/scwx-qt.cmake
@@ -464,8 +464,8 @@ target_compile_options(supercell-wx PRIVATE
 
 if (MSVC)
     # Don't include Windows macros
-    target_compile_options(scwx-qt PRIVATE /D "NOMINMAX")
-    target_compile_options(supercell-wx PRIVATE /D "NOMINMAX")
+    target_compile_options(scwx-qt PRIVATE -DNOMINMAX)
+    target_compile_options(supercell-wx PRIVATE -DNOMINMAX)
 
     # Enable multi-processor compilation
     target_compile_options(scwx-qt PRIVATE "/MP")
diff --git a/wxdata/wxdata.cmake b/wxdata/wxdata.cmake
index 91dc192a..f0507326 100644
--- a/wxdata/wxdata.cmake
+++ b/wxdata/wxdata.cmake
@@ -250,7 +250,7 @@ target_compile_options(wxdata PRIVATE
 
 if (MSVC)
     # Don't include Windows macros
-    target_compile_options(wxdata PRIVATE /D "NOMINMAX")
+    target_compile_options(wxdata PRIVATE -DNOMINMAX)
 
     # Enable multi-processor compilation
     target_compile_options(wxdata PRIVATE "/MP")